4-56 

iFsl 


UC-NRLF 


SM 


>• 


tUUCATION  D6P1 


"NW 


UNIVERSITY  OF  CALIFORNIA  PUBLICATIONS 

IN 

PSYCHOLOGY 

Vol.  2,  No.  3,  pp.  199-265  May  8,  1916 


THE  PSYCHOLOGY  AND  PHYSIOLOGY 
OF  MIRROR -WRITING 


BT 

JUSTIN    K.  FULLER 


UNIVERSITY  OF  CALIFORNIA  PRESS 
BERKELEY 


UNIVERSITY   OF   CALIFORNIA   PUBLICATIONS 

Note.— The  University  of  California  Publications  are  offered  in  exchange  for  the  publi 
cations  of  learned  societies  and  institutions,  universities  and  libraries.  Complete  lists  oJ 
all  the  publications  of  the  University  will  be  sent  upon  request.  For  sample  copies,  lists 
of  publications  or  other  information,  address  the  Manager  of  the  University  Press,  Berkeley, 
California,  U.  S.  A.  All  matter  sent  in  exchange  should  be  addressed  to  The  Exchange 
Department,  University  of  California  Library,  Berkeley,  California,  U.  S.  A. 

OTTO  HARRASSOWITZ,  R.   FRIEDLAENDER  &  SOHN, 

LEIPZIG.  BERLIN. 

Agent  for  the  series  in  American  Arch-  Agent  for  the  series  in  American  Arch- 
aeology and  Ethnology,  Classical  Philology,  aeology  and  Ethnology,  Botany,  Geography, 
Education,  History,  Modern  Philology,  Geology,  Mathematics,  Pathology,  Physi- 
Philosophy,  Psychology.  ology,  Zoology  and  Memoirs. 

PSYCHOLOGY.— George  M.  Stratton,  Editor.    Price  per  volume  $3.50. 

Cited  as  Univ.  Calif.  Publ.  PsychoL 

Vol.  1.  1.  The  Judgment  of  Difference,  with  Special  Reference  to  the  Doctrine  of 
the  Threshold,  in  the  Case  of  Lifted  Weights,  by  Warner  Brown. 
Pp.  1-71,  4  text  figures.  September,  1910 $0.50 

2.  The  Process  of  Abstraction,  an  Experimental  Study,  by  Thomas  Verner 

Moore.    Pp.  73-197,  6  text  figures.    November,  1910 1.00 

3.  The  Judgment  of  Very  Weak  Sensory  Stimuli,  with  Special  Reference 

to  the  Absolute  Threshold  of  Sensation  for  Common  Salt,  by  Warner 
Brown.    Pp.  199-268,  plates  1-4.    February,  1914 60 

4.  Habit  Interference  in  Sorting  Cards,  by  Warner  Brown.    Pp.  269-S21. 

April,  1914 „.      .50 

5.  Diurnal  Variations  in  Memory  and  Association,  by  Arthur  I.  Gates.    Pp. 

323-344.    March,  1916 .20 

VoL  2.  1.  Variations  in  Efficiency  During  the  Day,  Together  with  Practice  Effects, 
Sex  Differences,  and  Correlations,  by  Arthur  I.  Gates.  Pp.  1-156. 
March,  1916 1.50 

2.  Experiments  on  Attention  and  Memory,  with  Special  Reference  to  the 

Psychology  of  Advertising,  by  J.  M.  Levy.    Pp.  157-197.    April,  1916..     .40 

3.  The  Psychology  rand  Physiology  of  Mirror-Writing,  by  Justin  K.  Fuller. 

Pp.  199-265.     May,  1916 65 

PHILOSOPHY. — George  H.  Howison  Editor.    Price  per  volume  $2.00. 

Cited  as  Univ.  Calif.  Publ.  Philos. 

The  first  volume  of  the  University  of  California  Publications  in  Philosophy  appeared  in 
November,  1904,  and  was  prepared  in  commemoration  of  the  seventieth  birthday  of  Pro- 
fessor George  Holmes  Howison,  under  the  direction  of  a  committee  of  his  pupils  composed 
of  Evander  Bradley  McGilvary,  Charles  Henry  Rieber,  Harry  Allen  Overstreet  and  Charles 
Montague  Bakewell.  The  price  of  the  volume  is  $2.  It  may  be  had  bound,  or  the  papers 
may  be  obtained  separately..-  Jts  contents  aje:  : 

Vol.  1.    1.  The  Summuta«^onum,\byi^anAer  Bradley  McGilvary.    Pp.  1-27 .25 

2.  The  Essentials  of  Human  Faculty,,^  Sidney  Edward  Mezes.    Pp.  28-55     .25 

3.  Some  Spieitjfte  'ApWoglpsJ  for  £vil,  J)y  George  Malcolm  Stratton.    Pp. 

56-71:  ".:.r..::.^.^.:.:'....!^.:.:  .•.:„!:...:.: 15 

4.  Pragmatism  and  the  a  priori,  by  Charles  Henry  Rieber.    Pp.  72-91 20 

5.  Latter-day  Flowing-Philosophy,  by  Charles  Montague  Bakewell.     Pp. 

92-114 20 

6.  Some  Problems  in  Evolution  and  Education,  by  Ernest  Norton  Hen- 

derson.    Pp.  115-124 10 

7.  Philosophy  and  Science  in  the  Study  of  Education,  by  Jesse  Dismukes 

Burks.    Pp.  125-140 15 

8.  The  Dialectic  of  Bruno  and  Spinoza,  by  Arthur  Oncken  Love  joy.    Pp. 

141-174 . 35 

9.  The  Logic  of  Self -Realization,  by  Henry  Waldgrave  Stuart.  Pp.  175-205     .so 

10.  Utility  and  the  Accepted  Type,  by  Theodore  de  Lopez  de  Laguna.    Pp. 

206-226 .20 

11.  A  Theory  of  the  Syllogism,  by  Knight  Dnnlap.    Pp.  227-235 10 

12.  The  Basal  Principle  of  Truth-Evaluation,  by  Harry  Allen  Overstreet. 

Pp.  236-262 25 

Vol.  2.    1.  The  Dialectic  of  Plotinus,  by  H.  A.  Overstreet.    Pp.  1-29.    May,  1909..!!     .25 
2.  Two  Extensions  of  the  Use  of  Graphs  in  Formal  Logic,  by  W.  E.  Hock- 
ing.   Pp.  31-34.     May,  1909 .15 

S.  On  the  Law  of  History*  by  W.  E.  Hocking.    Pp.  45-65.    September,  1909    .80 


UNIVERSITY    OF   CALIFORNIA    PUBLICATIONS 

IN 

PSYCHOLOGY 

Vol.  2,  No.  3,  pp.  199-265  May  8,  1916 


THE  PSYCHOLOGY  AND  PHYSIOLOGY  OF 
MIRROR-WRITING 


BY 

JUSTIN  K.  FULLER 
11 


The  research  to  which  the  following  pages  are  devoted  was 
begun  in  1911,  and  was  continued  with  several  interruptions  to 
the  end  of  the  academic  year  1913. 

I  avail  myself  of  this  opportunity  to  express  my  thanks  to 
the  officials  of  the  Napa  State  Hospital;  the  California  Home 
for  the  Care  and  Training  of  Feeble-Minded  Children,  at 
Eldridge ;  the  California  Institution  for  the  Deaf  and  Blind,  at 
Berkeley;  and  to  other  individuals  by  whose  courtesy  I  was 
enabled  to  gather  much  of  the  data  for  this  paper.  I  wish  to 
thank  Professor  Brown  for  affording  me  all  possible  facilities 
in  the  psychological  laboratory,  and  for  his  kind  assistance. 
I  am  under  deep  obligation  to  Professor  S.  S.  Maxwell,  of  the 
department  of  physiology,  for  reading  the  manuscript.  The 
unfailing  kindness,  and  the  constant  interest  in  my  work  evinced 
by  Professor  Stratton,  I  shall  remember  always. 

Berkeley,  California.  J.  K.  F. 


991885 


200     University  of  California  Publications  in  Psychology  tv°L-  2 

CONTENTS 

PAGE 

1.  Introduction   199 

1.  Definition  200 

2.  Conditions   hitherto   recognized    as   favorable   to   mirror- 

writing    201 

3.  A  working  explanation  of  mirror-writing  202 

4.  Three  kinds  of  reversals  203 

5.  Summary   of   explanations   of  mirror-writing   offered   by 

various  observers  204 

6.  Classification  of  previous  theories  214 

2.  Experimental  findings  under  various  conditions 215 

1.  Hypnosis    : 215 

2.  Hysteria 216 

3.  Drugs  217 

4.  Abstraction    220 

5.  Insane   220 

6.  Hemiplegia    220 

7.  Feeble-minded  221 

8.  Deaf  and  dumb  222 

9.  Blind   222 

10.  Normal   children  223 

11.  Persons  with  special  manual  training  223 

12.  University  students  225 

13.  Reversed  visual  field  226 

3.  The  explanation  of  mirror-writing 227 

1.  The  Physiological  factor  in  mirror-writing 227 

2.  The  Psychological  factor  in  mirror-writing 237 

3.  Experimental  relations  246 

4.  Recapitulation    258 

4.  Relation  of  the  present  theory  to  that  of  others 260 


INTRODUCTION 

1.  DEFINITION 

Mirror-writing  is  characterized  by  a  reversal  of  the  form  and 
arrangement  of  the  letters,  which  appear  as  if  ordinary  writing 
were  held  before  a  mirror.  It  in  turn  becomes  legible  and  has 
the  appearance  of  ordinary  writing,  when  seen  in  a  mirror. 


Fuller:  Mirror-Writings.  201 


2.  CONDITIONS  HITHERTO  RECOGNIZED  AS  FAVORABLE  TO  MIRROR- 

WRITING 

It  will  be  advisable  to  assemble  in  the  form  of  a  brief  resume 
the  various  conditions  under  which  mirror-writing  has  been 
observed.  It  is  found  as  a  spontaneous  occurrence  only  in  left- 
handed  children,  or  in  adults  after  right-handed  paralysis, 
though  it  can  be  acquired  by  anyone  after  practice.*1  It  may  be 
deliberately  performed  as  a  trick50  or  as  an  amusement.12  The 
ability  is  not  at  all  rare,  and  may  be  possessed  by  all  persons  but 
remain  unobserved.3  The  latent  ability  to  write  mirrorwise  is 
ordinarily  made  evident  in  adults  by  some  lesion  suddenly  ren- 
dering the  right  arm  useless.  But  paradoxically,  nearly  every 
child  at  a  certain  period  of  its  development  will  be  found  to 
produce  spontaneous,  fragmentary  mirror-writing  with  the  right 
hand.31  Children  whose  writing  is  still  forming  may  be  observed 
to  make  spontaneous  fragmentary  left-hand  reversals,  especially 
in  the  up-and-down  turnings  of  single  letters,  figures,  etc. 
Similar  reversals  may  be  seen  in  the  left-hand  writing  of  many 
adults  who  write  usually  with  the  right  hand.5  Left-handed 
mirror-writing  may  be  a  physiological  sequela  of  weakness  by 
disease,  of  weak-mindedness  in  children,  of  left-handedness,  or 
merely  of  absent-mindedness  in  a  normal  person.55  Occasionally 
it  is  seen  in  feeble-minded  or  left-handed  children,  or  in  a 
patient  who  has  had  right  hemiplegia  in  early  life.47  Numerous 
cases  have  been  observed  to  follow  right-sided  hemiplegia.  It 
has  been  ranked  as  first  among  the  manifestations  of  aphasia13 
and  on  the  other  hand  has  been  supposed  to  have  no  very  special 
connection  with  aphasia.9  It  has  been  spoken  of  as  a  congenital 
tendency,  almost  a  defect,  in  left-handed  children.12  A  neurotic 
inheritance  may  aid  in  its  acquirement;  it  is  met  with  in  some 
forms  of  mental  weakness,  and  in  some  conditions  of  mental 
disorder  allied  to  the  hysterical;  it  is  more  common  among 
women  than  among  men,  and  is  more  easily  acquired  by  the 


*The  superior  figures  refer  to  the  List  of  References,  pp.  262-265. 


202- •*  UtMrlily'^f  ^California  Publications  in  Psychology  [VOL-  2 


: n-^rvous  c people;  it  may  occur  in  cases  of  moral 
perversion  and  may  be  only  temporary,  recurring  with  the 
other  symptoms  of  the  disorder.67  Some  mirror-writers  belong 
to  the  class  of  learned  idiots,  or  idiots  savants.8  It  is  more 
common  among  high-grade  imbeciles  than  among  the  left- 
handed.64  As  a  pathological  condition,  left-handed  mirror- 
writing  is  rather  common  in  children  with  impaired  intelli- 
gence, in  deaf  mutes,  the  blind,  and  in  cases  of  katatonia.31  Also 
it  has  been  observed  in  cases  of  dementia  praecox  (under  which 
heading  katatonia  has  been  included).54  Severe,  and  as  a  rule 
chronic  cerebral  diseases,  cerebral  degeneration,  or  feeble-mind- 
edness  may  cause  its  appearance.59  It  may  be,  but  is  probably 
very  rarely,  indicative  of  nervous  disease,55  and  is  not  in  itself 
a  sign  of  mental  defect  although  it  is  seen  in  such  cases.45  Vari- 
ous observers  have  claimed  for  it  only  pathological  significance, 
but  the  majority  agree  that  it  is  the  normal  writing  for  the  left 
hand. 

3.  A  WORKING  EXPLANATION  OP  MIRROR- WRITING 

Reversed  writing  is  produced  when  the  hand  unaccustomed 
to  writing  produces  the  series  of  motions  to  which  the  other 
hand  is  accustomed  (symmetrical  accompanying  movements). 
The  nervous  relations  whereby  this  unusual  mode  of  expression 
is  attained  has  long  been  a  question  of  interest  wherever  observ- 
ers have  noted  its  occurrence.  The  diversity  of  conditions  which 
may  lead  to  the  production  of  mirror-writing  has  undoubtedly 
contributed  in  no  small  part  to  the  confusion  which  attaches  to 
the  subject.  An  indication  of  the  variety  of  these  conditions  has 
been  given  above,  and  a  notion  of  the  resulting  confusion  may  be 
obtained  from  the  hypotheses  of  the  various  authors,  to  follow  on 
pp.  204  if.  Although  the  explanation  of  mirror- writing  is  a  sub- 
ject of  controversy,  it  is  generally  admitted  that  the  one  hand,  or 
more  generally  the  entire  side  of  the  body,  or  any  part  thereof, 
acquires  skill  from  the  practice  of  the  opposite  part.  Thus,  if 
certain  groups  of  muscles  and  nerves  on  the  right  side  have  been 


19163  Fuller:  Mirror-Writing  203 

trained  to  perform  certain  definite  movements  (resulting  in  a 
centrifugal  writing),  it  will  be  the  same  definite  groups  on  the 
left  side  which  have  gained  in  efficiency.  The  ability  to  write 
in  a  centrifugal  direction  with  the  left  hand  is  due  almost 
entirely  to  this  "cross-education". 


4.  THREE  KINDS  OF  REVERSAL 

Written  symbols  may  be  reversed  as  a  result  of  at  least  three 
fundamentally  different  types  of  control.  I  am  primarily  inter- 
ested in  but  one  of  these  types.  This  may  be  defined  as  the 
spontaneous,  automatic,  unpracticed  kind  which  in  certain  rare 
instances  has  been  noticed  to  accompany  or  follow  such  conditions 
as  are  mentioned  on  pp.  201  ff.  (except  right-handed  reversals 
by  right-handed  individuals  or  vice  versa).  The  mirror-writing 
which  occurs  in  all  of  these  conditions,  I  have  classed  together, 
because  (a)  the  mechanism  for  the  reversed  writing  is  similar  in 
all  these  cases;  (&)  there  are  certain  psychological  aspects  com- 
mon to  these  various  conditions;  and  (c)  all  other  forms  of 
mirror-writing  are  distinctly  of  a  different  order. 

(a)  The  motor  complex  for  reversed  writing  is  a  constant 
factor.  It  will  be  considered  at  length  in  Part  III,  Section  1. 

(6)  The  psychological  aspects,  when  present,  remove  certain 
inhibitions  to  the  functioning  of  the  reversed-writing  motor 
complex.  The  inhibitory  process  may  be  likened  to  a  brake, 
which  when  released,  will  allow  the  mechanism  to  glide  along 
unhindered.  The  psychological  factor  is  thus  highly  favorable 
to  mirror-writing.  It  will  be  treated  in  Part  III,  Section  2.  The 
relations  of  the  various  experiments  of  Part  II  to  the  reversed 
mechanism  and  to  the  psychological  factors  will  be  taken  up  in 
Section  3  of  Part  III.  In  this  part,  I  will  endeavor  to  explain 
the  interconnection  which  exists  in  all  forms  of  mirror-writing. 

(c)  The  other  forms  of  mirror-writing  may  be  divided  into 
(1)  the  form  which  results  from  a  conscious  attentive  endeavor 
to  reverse  the  writing;  this  form  will  be  considered  briefly  in 
Part  III,  Section  2.  (2)  A  kind  which  occurs  usually  only  in 


204     University  of  California  Publications  in  Psychology  tv°L-  2 

single  letters  or  in  fragments  of  a  letter,  and  is  due  primarily 
to  a  confusion  of  the  left-right  relation  of  objects  in  space.  This 
will  also  be  considered  in  Part  III,  Section  2. 


5.  SUMMARY  OF  EXPLANATIONS  OF  MIRROR- WRITING  OFFERED  BY 
VARIOUS  OBSERVERS 

Clapham18  believes  that  abduction  is  the  more  convenient 
movement  for  writing.  He  studied  a  child  who  could  write  with 
the  left  hand  almost  equally  well  in  three  styles — namely, 
mirrorwise  (the  style  first  learned),  rightwards  (as  she  was 
made  to  write  in  school),  and  with  alternate  lines  in  opposite 
directions  (when  she  was  absent-minded).  He  sees  a  parallel 
between  this  case  and  the  history  of  writing,  which  was  left- 
wards in  the  earliest  Greek  and  Etruscan  period,  later  "plough- 
wise",  and  finally  rightwards. 

Wilks69  observes  that  if  the  arms  be  rolled  about  one 
another,  the  movements  are  exactly  alike.  If  the  arms  are 
extended  to  the  sides  during  the  continuance  of  the  same  rela- 
tive movements,  the  right  hand  will  trace  ordinary  writing,  and 
the  left  hand  mirror-writing.  The  movements  and  the  results 
correspond.  Hence  skill  in  copying  with  the  left  hand  the 
usual  form  of  writing  is  acquired  only  after  long  effort  to  over- 
come the  awkward  use  of  the  arm,  due  to  the  different  set  of 
muscles  that  are  brought  into  play. 

Wray71  says  that  left-handedness  must  not  be  taken  as  an 
indication  of  the  anatomical  superiority  of  the  right  hemisphere. 
Our  ability  to  write  mirrorwise  more  easily  than  rightward  with 
the  left  hand,  rests  upon  the  tendency  to  automatism  of  move- 
ment in  an  opposite  direction  brought  about  by  the  movements 
of  the  hands  in  opposite  directions  while  walking. 

List47  simply  notes  that  mirror- writers  use  the  left  hand; 
hence  the  natural  result  is  to  write  from  right  to  left. 

Durand21  observed  that  among  intelligent  persons  mirror- 
writing  with  either  hand  is  difficult,  because  of  the  very  strong 
habit  of  writing  from  left  to  right ;  but  that  in  the  unintelligent 


1916]  Fuller:  Mirror-Writing  205 

there  is  an  aptitude  to  write  either  style  with  the  left  hand.  The 
image  of  normal  writing  being  less  strong  in  the  latter  case, 
the  inclination  is  largely  unhampered  by  it. 

Grace  Peckham55  reasons,  a  priori,  that  mirror-writing  may 
indicate  a  change  in  the  perception  of  the  nerve  centres  of  the 
brain.  But  if  this  were  so,  the  patient  should  read  this  form 
of  writing  more  easily  than  the  normal,  a  condition  she  has  been 
unable  to  verify,  with  possibly  one  exception,  in  the  literature. 
She  therefore  attributes  mirror-writing  in  every  case  to  a 
mechanical  cause,  the  person  finding  it  easier  to  write  in  a  cen- 
trifugal direction :  the  ' '  association  of  ideas  and  muscular  action 
making  this  so."  The  reason  lies  in  a  physiological,  not  a 
pathological,  condition ;  therefore  anyone,  when  not  exercising 
care  and  forethought,  might  be  expected  to  write  in  a  reversed 
direction  with  the  left  hand.  Similarly  the  so-called  "patho- 
logical" cases  of  mirror- writing  are  probably  brought  about 
through  weakness  by  disease,  weak-mindedness  in  children,  or 
simply  as  a  result  of  left-handedness. 

Erlenmeyer23  believed  abduction  to  be  the  natural  method 
for  executing  all  finer  movements.  His  corollary  to  this  is  that 
writing  toward  the  right  is  a  result  of  right-handedness,  and 
the  greater  development  of  the  left  cerebral  hemisphere  is 
the  result  of  right-handedness,  not  its  cause.  Consequently 
those  who  wrote  from  right  to  left  must  have  been  left-handed, 
for  the  right  hand  follows  the  general  tendency  of  abduction. 

Ireland,38  while  he  admits  that  most  actions  requiring  skill 
are  more  easily  executed  in  a  centrifugal  direction,  yet  criti- 
cizes Erlenmeyer 's  illustrations.  For  instance,  Ireland  has  seen 
quite  as  brilliant  passages  on  the  piano  done  in  a  centripetal  as 
in  a  centrifugal  manner.  This  is  also  true  of  many  other  deli- 
cate operations,  such  as  using  the  sling,  bowling  and  batting  in 
cricket,  fencing,  swimming,  sewing,  and  so  on.  Ireland35  38  has 
shown  by  a  number  of  experiments  and  observations  that  there 
is  a  physiological  tendency  for  left-handed  children  to  write 
mirrorwise.  This  tendency  occasionally  prevails  in  adults  who 
for  some  reason  use  the  left  hand.  As  an  instance,  some  Arabic 


206     University  of  California  Publications  in  Psychology  CV°L-  2 

characters  were  unconsciously  reversed  by  the  left  hand  of  a 
subject.  Hemiplegia  of  the  right  side  is  also  an  important  factor 
in  bringing  about  left-handed  reversals.  His  general  conclusion 
is  a  modification  of  Erlenmeyer's  theory,  with  the  additional 
idea  that  two  mental  images  are  formed,  one  on  each  hemisphere 
of  the  brain.  The  image  on  the  right  is  the  exact  mirror-reverse 
of  the  one  on  the  left,  so  that  the  left-handed  writer  would  trace 
)  for  (. 

Kingman42  cites  several  tests  to  illustrate  the  old  idea  that 
abduction  movements  are  the  more  natural  and  graceful  for 
either  hand.  He  also  supposes  that  "analogous  pictures  re- 
versely formed"  are  developed  in  the  right  brain  conjointly  with 
those  in  the  left  in  two  ways :  ( 1 )  to  some  extent  co-ordinately ; 
(2)  by  what  may  be  termed  an  overflow  process,  occurring  either 
concurrently  or  because  the  left  centers  have  attained  a  max- 
imum degree  of  development  or  training.  Further,  the  conclu- 
sion is  that  the  image  on  the  left  cortex  may  be  "called  into 
play  with  either  left  or  right  hand  to  produce  ordinary  writing", 
and  the  converse.  However,  writing  from  left  to  right  with 
the  left  hand  is  as  unnatural  as  mirror-writing  with  the  right 
hand,  which  explains  why  mirror-writing  is  most  frequently  seen 
in  those  who  are  not  up  to  the  standard  of  the  normal  educated 
man.  The  latter  is  able  to  make  the  transposition  of  graphic 
memory  at  will,  and  consequently  write  either  form  with  either 
hand.  And  "both  of  these  graphic  picture  centres  may  also 
be  correlated  with  the  appropriate  muscle  motor  centres  to 
produce  mirror  or  ordinary  writing  through  the  medium  of 
the  toes,  lips,  elbows,  or  any  other  part  to  which  suitable  appa- 
ratus can  be  attached." 

Leichtenstern43  assumes  that  the  left  hand  receives  its  stim- 
ulus from  the  right  cortex,  and  following  its  natural  desire  for 
abduction  movement,  produces  mirror-writing.  He  speaks  of  a 
"peculiar  opposition"  found  in  the  left  hand  to  writing  right- 
wards, thus  making  mirror-writing  the  easier  form  in  all  cases. 

Acker1  agrees  that  writing  is  more  easily  formed  in  a  cen- 
trifugal direction.  Also  that  mirror-writing  has  followed  dis- 


1916]  Fuller:  Mirror-Writing  207 

ease  of  the  left  side  of  the  brain  in  numerous  recorded  cases. 
He  states  that  there  is  a  physiological  tendency  for  left-handed 
children  to  fall  into  mirror-writing. 

Buchanan12  cites  certain  cases  which  "point  with  some  clear- 
ness to  the  fact  that  the  person  who  is  using  the  right  side  of  the 
brain  .  .  .  has  a  very  strong  tendency  to  write  mirror- 
wise  ;  and  we  may  assume  that  in  the  case  of  the  left-handed 
person  the  right  side  of  the  brain  is  so  used."  The  author 
believes  with  Erlenmeyer  that  there  is  a  greater  natural  tend- 
ency towards  abduction  than  towards  adduction. 

Mills50  holds  that  "special  convolutions  in  the  right  hemi- 
sphere have  in  a  quiescent  and  undeveloped  state  the  same  func- 
tions which  are  active  in  the  corresponding  convolutions  of  the 
left  hemisphere."  Impressions  received  by  the  left  cortex  of  a 
normal  person  are  recognized  as  normal  or  usual  images,  and 
as  being  right  side  up.  The  images  formed  on  the  right  cortex 
are  usually  suppressed.  When  these  parts  of  the  left  cortex  are 
injured,  their  functions  are  re-acquired  through  the  arousing 
and  developing  of  the  latent  activities  of  the  right  hemisphere. 
For  those  cases  of  mirror-writing  occurring  in  the  absence  of 
direct  lesion  of  the  left  cortex  (e.g.,  injury  to  right  arm),  he 
assumes  that  the  development  of  the  left  cortex  is  arrested  and 
the  individual  is  guided  by  the  images  on  the  right  cortex. 
Similarly,  mere  use  of  the  left  arm  may  cause  the  images  of 
the  right  cortex  to  be  aroused  sufficiently  to  guide  the  arm.  A 
possible  explanation  for  some  isolated  cases  of  left-handed 
reversals  may  be  that  the  individual  can  write  with  readiness 
in  the  centrifugal  direction. 

Bastian9  thinks  mirror-writing  has  no  very  special  connection 
with  aphasia.  He  believes  that  a  centre  for  writing  movements 
may  be  developed  in  either  hemisphere  for  writing  with  the 
opposite  hand.  He  criticises  Elder's  belief  that  there  exists  but 
one  special  centre,  located  in  the  left  brain:  for  if  this  were 
so,  how  would  one  account  for  the  fact  that  only  five  per  cent 
of  the  subjects  tested  by  Elder  were  mirror-writers?*  Bastian 


*See  p.  210. 


208     University  of  California  Publications  in  Psychology  tv°L-  2 

inclines  to  the  view  that  "writing  movements  of  the  left  hand 
are  controlled  by  the  conjoint  activity  of  visual  and  kinesthetic 
centres  in  the  right  hemisphere,  just  as  the  writing  movements 
of  the  right  hand  are  controlled  or  co-ordinated  by  similar 
centres  in  the  left  cerebral  hemisphere." 

Bruce1*  deduces  from  his  study  of  a  case  of  dissociated  per- 
sonality, in  which  "the  right  and  left  brain  alternately  exert  a 
preponderating  influence  over  the  motor  functions",  the  sep- 
arate control  of  the  sides  of  the  body  each  by  the  opposite  cor- 
tex. Mirror-writing  was  the  usual  form  when  the  patient  was 
in  the  left-handed  stage. 

Anden4  believes  "that  there  are  potential  kinesthetic  centres 
for  writing  on  each  side  of  the  brain."  For  left-handed 
rightward  writing  the  impulses  from  the  motor  centre  which 
co-ordinate  the  movements  of  the  left  hand  are  "reinforced  and 
overlaid  by  a  train  of  motor-memory  impulses  from  the  cells  of 
the  cheiro-kinesthetic  centre  for  the  right  hand."  For  this 
reason  mirror-writing  is  generally  found  in  young  children  and 
is  usually  transitory,  disappearing  as  the  right  hand  becomes 
more  facile  in  the  use  of  the  pen. 

Peretti57  supposes  a  dual  brain  action  similar  to  that  assumed 
by  Ireland.  He  believes  that  mirror-writing  in  hemiplegia  is 
due  to  the  mental  obtuseness  of  the  patient,  rendering  him  like 
a  young  child.  He  says  that  a  woman  hypnotized  on  the  left 
side  of  the  body,  which  he  assumes  implicates  only  the  right 
hemisphere,  traced  mirror-writing  with  the  right  hand:  and 
when  hypnotized  on  the  right  side  of  the  body,  she  wrote  with 
the  left  hand  towards  the  right. 

Bianchi10  notes  that  a  characteristic  of  ordinary  writing  is 
that  every  people  uses  the  right  hand,  no  matter  in  what  direc- 
tion the  characters  are  traced;  and  that  the  "psycho-mechan- 
ical" act  of  writing  is  executed  by  a  reflex  mechanism  similar 
to  that  of  oral  speech,  the  sensation  coming  for  the  most  part 
through  the  organs  of  sight,  and  to  a  lesser  degree  through  the 
"auditive"  sense.  He  thinks  it  impossible  that  the  seat  for  the 
disposition  of  the  words  and  the  impression  of  the  motions 


1916]  Fuller:  Mirror-Writing  209 

necessary  for  their  formation,  and  the  impression  of  the  image 
of  the  words,  should  be  only  in  the  left  hemisphere.  By  their 
presence  in  the  right  hemisphere,  even  to  a  much  slighter 
degree,  he  accounts  for  the  cause  of  both  the  pathological 
(hemiplegic)  and  the  more  normal  form  of  mirror- writing.  He 
says: 

In  a  hemiplegia  of  the  right  side  it  will  therefore  happen  that  the 
image,  not  calling  forth,  on  the  left  hemisphere,  any  centrifugal  mo- 
tion in  the  muscles  on  the  right  hand,  will  oblige  the  extensor  cellular 
groups  in  the  sound  right  hemisphere  to  write  from  the  left,  because  of 
the  preserved  remembrance  of  the  muscular  combinations  associated 
with  the  image  of  the  word. 

Hence,  there  will  be  an  identical  centrifugal  motion  giving 
lithographic  writing.  If  one  writes  centripetally  with  the  left 
hand,  the  muscle  groups  are  antagonists  to  the  muscle  groups 
used  in  right-hand  ordinary  writing,  and  thus  give  an  "insup- 
portable contraction. ' ' 

Burr  and  Crow14  think  that  associated  movements  are  due 
to  bilateral  representation  in  the  cerebral  motor  cortex  of  the 
parts  affected,  plus  motor  overflow.  Thus,  these  movements 
result  if  an  adult  has  not  learned  to  restrict  completely  the 
random  movements  of  the  infant.  Mirror-writing,  depending 
upon  these  principles,  offers  a  less  complex  problem  than  the 
wider  question  of  associated  movements  in  general.  Simultane- 
ous writing  with  the  two  hands  is  not  naturally  identical,  but 
opposed.  In  this  fashion,  the  ordinary  educated  man  will  write 
rightwards  with  the  left  hand  only  if  he  "uses  his  will  to  make 
himself  do  so",  and  the  real  reason  imbeciles  write  mirrorwise 
with  the  left  hand  is  not  that  they  are  imbeciles,  but  because 
being  imbeciles  they  "permit  the  left  hand  to  do  what  it  will 
without  trying  to  control  it." 

Rudolf60  thinks  that  we  get  a  double  image  in  the  visual 
centres,  the  one  in  the  right  side  being  the  reverse  of  the  one  in 
the  left.  The  impression  in  the  right  cortex  of  ordinary  people  is 
so  poor,  however,  that  it  is  not  used  for  left-handed  writing. 
Instead,  ordinary  writing  is  slowly  traced  out.  But  in  a  natur- 
ally left-handed  person  the  impression  on  the  right  brain  is 


210     University  of  California  Publications  in  Psychology  tv°L-  2 

good,  and  therefore  mirror-writing  is  the  natural  type  for  the 
left  hand.  Moreover,  it  would  result  that  all  persons  showing 
right  hemiplegia  with  mirror-writing  are  either  left-handed  or 
ambidextrous. 

Campbell16  is  not  convinced  that  writing  is  exclusively  the 
function  of  one  hand,  although  in  writing  "forwards"  with 
the  left  hand  the  movements  do  not  correspond  to  the  usual 
right-handed  movements;  yet  one  may  learn  this  form  quite 
easily,  and  it  does  not  seem  that  there  are  many  disadvantages 
attached  to  such  an  accomplishment. 

Elder22  differs  from  the  view  that  there  are  two  writing 
centres.  He  tested  451  persons  of  different  ages  and  sexes  and 
found  that  5.1  per  cent,  when  first  bidden  to  write  with  the 
left  hand,  reversed  their  script.  He  finds  that  the  left-handed 
mirror-writing  agrees  in  every  detail  with  the  usual  right- 
handed  writing,  and  therefore  must  be  guided  by  the  same 
centre.  This  centre  could  not  be  the  visual  centre,  else  the 
writing  would  be  in  the  usual  shape  and  not  mirrorwise. 

Allen's3  conclusion  is  that  the  true  graphic  center  is  not 
coincident  with  either  of  the  motor  centers,  but  superior  to  them 
all.  Thus  he  suggests  that  all  the  messages  start  from  the  same 
region  of  the  brain.  But  at  a  lower  level  they  are  turned  into 
different  channels  leading  to  analogous  but  sometimes  heter- 
onymous  groups  of  muscles. 

Russell61  agrees  with  the  theories  of  Allen  and  Elder, 
although,  in  the  case  he  observed,  the  mirror-writing  was  very 
faulty  and  bore  no  resemblance  to  the  normal  right-handed 
writing  of  the  patient.  The  single  cortical  centre  should 
innervate  homologous  muscles,  making  the  resulting  left-handed 
mirror-writing  perfectly  normal.  He  intimates  that  the  fibres 
connecting  Broca's  convolution  with  the  lower  centres  are  dam- 
aged, rather  than  the  special  centre  itself.  In  addition,  the 
frequency  of  occurrence  of  mirror- writing  in  aphasia  "suggests 
that  there  may  possibly  be  some  special  connection  between  the 
two  conditions." 

Jones,40  although  hazarding  no  explanation  for  the  occur- 


1916]  Fuller:  Mirror-Writing  211 

rence  of  mirror-writing,  gives  a  rather  good  destructive  criticism 
of  some  of  the  existing  views.  The  only  explanation  which 
seems  to  him  at  all  adequate,  is  that  given  by  Mills  in  the 
Encyclopedia  Medica.  As  most  mirror-writing  is  left-handed, 
the  movements  are  primarily  guided  by  the  left  cerebral  cortex 
through  some  preponderating  influence  which  the  cells  on  the 
left  side  have  over  those  on  the  right.  As  a  result  the  move- 
ments of  the  left  hand  are  symmetrical  with  those  of  the  right, 
and  because  the  same  relative  muscle-groups  on  the  two  sides 
are  used,  mirror-writing  will  be  the  left-handed  type.  Some 
stress  is  placed  upon  the  particularly  close  association  of  the 
two  hemispheres  through  the  corpus  callosum.  Even  this 
explanation,  says  Jones,  affords  but  little  light  on  the  subject. 
He  is  especially  bitter  towards  the  * '  retinal-image ' '  and  ' '  mental-, 
image"  hypotheses.  He  remarks  that  the  blind  suddenly  given 
vision  do  not  interpret  it  as  inverted. 

Smith63  notes  that  the  various  idiosyncrasies  of  right-handed 
writing  will  be  copied  in  reverse  by  the  left,  but  that  these 
peculiarities  will  not  be  followed  if  the  right  hand  writes 
in  reverse.  He  is  not  able  to  decide  whether  this  phenomenon  is 
due  to  more  or  less  facility  of  hand  movement  (as  suggested 
by  Erlenmeyer)  or  whether  it  lies  deeper,  in  some  unilateral 
brain  perception. 

A  view  having  great  divergence  from  previous  hypotheses 
was  offered  by  Hale  and  Kuh.31  These  authors  formulate  a 
theory,  based  upon  the  relation  of  objects  in  space  to  the  com- 
plicated process  of  mental  co-ordination.  They  call  attention  to 
the  fact  that  right-handed  fragmentary  reversals  are  of  far 
more  frequent  occurrence  than  left-handed  mirror- writing ;  an 
observation  which,  if  it  had  been  made,  was  hitherto  con- 
sidered of  little  or  no  importance.  Only  by  laboriously  acquired 
experience  do  we  learn  to  interpret  the  inverted  image  on  the 
retina  and  produce  an  upright  writing.  The  child  and  the 
feeble-minded,  lacking  this  experience,  or  the  adult  suddenly 
deprived  of  it,  reproduces  the  visual  image  in  incorrect  spatial 
relation;  hence  the  mirrored  or  completely  inverted  writing. 


212     University  of  California  Publications  in  Psychology  tv°L-  2 

Complete  inversions  are,  however,  rare ;  as  the  lateral  relation- 
ship, being  the  last  and  hardest  to  acquire,  is  first  to  be  lost. 
They  claim  that  the  link  which  unites  all  the  various  states  in 
which  mirror-writing  shows  itself  is  an  imperfectly  developed 
(in  the  very  young  or  in  some  mental  deficients)  or  path- 
ologically disturbed  (after  hemiplegia  and  in  certain  acquired 
psychic  disturbances)  psychic  association  and  co-ordination. 
But  little  credence  is  placed  in  the  "abduction"  theory  of 
Erlenmeyer  as  an  explanation  for  mirror-writing,  because  if 
this  movement  were  a  very  powerful  stimulus,  mirror-writing  in 
right  hemiplegics  would  be  the  rule  rather  than  the  exception. 
The  criticism  of  Ireland's  theory  is  that  modern  physiological 
psychology  cannot  accept  with  such  completeness  the  dual  char- 
acter of  the  brain;  nor  does  this  theory  cover  all  cases. 

Sweeney64  attributes  mirror-writing  to  a  disarrangement  of 
sensory  impressions,  with  a  resulting  confusion  or  suppression 
of  one  or  more  of  the  factors  which  give  us  our  idea  of  the 
spatial  position  of  objects.  Thus,  a  case  of  astigmatism  may  so 
interfere  with  the  muscle  sense  as  to  prevent  the  proper  associa- 
tion in  the  mind  with  other  sensations  and  a  normal  transposi- 
tion of  the  retinal  image.  Mirror-writing  in  such  a  case  was 
completely  eradicated  by  glasses  that  removed  the  reflex  stimu- 
lation. The  reason  why  mirror-writing  is  reversed,  and  not 
inverted,  is  that  the  lateral  visual  field  is  more  extensive,  and 
muscular  movements  are  more  frequent  in  a  lateral  direction  and 
hence  more  easy  and  unconscious;  the  impressions  conveyed  to 
the  mind  are  less  in  degree  than  are  the  vertical;  the  latter  is 
a  more  purposive  stimulus,  and  impressions  conveyed  by  the 
muscular  sense  are  less  likely  to  be  overpowered  by  the  reflexes 
excited  by  eye-defects.  The  disarrangement  in  hemiplegia  ' '  may 
be  that  the  unaccustomed  use  of  the  other  hand  for  writing,  and 
the  confusion  between  former  muscular  habit,  memory  and  the 
effort  to  adapt  new  centres  to  an  unusual  task  would  produce  a 
reversal  of  writing  when  attention  is  not  directed  to  the  forma- 
tion of  words."  The  author  criticizes  Ireland's  assumption  of 
a  corresponding  but  reversed  image  in  the  right  brain  of  right- 


1916]  Fuller:  Mirror-Writing  213 

handed  individuals,  as  a  "rather  violent  hypothesis",  and  asks 
why,  if  this  be  so,  there  is  not  inverted  vision  as  well  as  hemian- 
opsia  when  the  visual  centre  of  the  left  hemisphere  is  destroyed 
— a  condition  which  does  not  exist.  Also,  he  claims  it  harzard- 
ous  to  explain  mirror-writing  on  the  basis  of  mechanical  ease, 
as  Peckham  does;  for,  if  so,  at  least  a  tendency  to  mirror- 
writing  should  be  shown  by  all  left-handed  individuals  begin- 
ning to  write,  and  not  by  a  small  percentage  only. 

Pendred56  inclines  to  the  view  that  "the  pictures  of  letters 
in  the  boy's  [referring  to  the  case  of  spontaneous  mirror- 
writing  he  is  studying]  memory  centre  are  incorrectly  stored 
and  incorrectly  reproduced."  He  thinks  that  the  receptive 
apparatus  in  the  occipital  lobes  may  "play  this  strange  prank 
with  the  naturally  inverted  pictures  of  letters  received  on  the 
boy's  retina."  He  notes  "that  the  letters  are  not  inverted,  as 
would  be  the  case  if  the  brain  merely  failed  to  right  the  retinal 
images. ' ' 

With  regard  to  the  sort  of  control  utilized  by  subjects  vol- 
untarily writing  reversedly,  Abt2  distinguishes  three  classes: 
(1)  Those  who  before  writing  represented  the  form  of  letters 
as  reversed — to  which  but  three  of  his  thirty  subjects  con- 
formed. This  method  was  found  to  be  slow  and  laborious,  the 
writer  was  apt  to  become  confused  and  there  was  frequent 
reversion  to  rightward  writing.  (2)  Those  who  depended  upon 
visual  representation  of  the  symmetrical  movement.  This  was 
the  usual  method  of  control.  Mistakes  were  rarely  errors  of 
reversion  to  rightward  writing  and  never  of  partial  reversion 
of  a  letter.  (3)  Those  for  whom,  apparently,  the  auditory 
motor  image  immediately  evoked  the  movement.  The  existence 
of  this  control  Abt  questions,  for  if  the  auditory  motor  image 
calls  forth  left-hand  mirror-writing,  how  can  it  call  forth  by  the 
same  mechanism  right-hand  mirror-writing? 

Downey20  questions  the  possibility  of  classing  six  of  her 
eight  subjects  (two  used  Abt's  first  method,  modified)  under 
Abt 's  second  heading ;  she  says :  ' '  For  why  may  there  not  be  a 
motor  as  well  as  a  visual  representation  of  a  movement?" 


214     University  of  California  Publications  in  Psychology  [VOL-  2 

Visual  representation  of  a  movement  was  rarely  spoken  of,  but 
grapho-motor  control  was  frequently  insisted  upon,  sometimes 
as  a  matter  of  anticipatory  imagery.  Downey  accepts  the  possi- 
bility of  a  purely  motor  representation  of  the  movement. 

6.  CLASSIFICATION  OF  PREVIOUS  THEORIES 

The   theories   of  mirror- writing  may   be   divided   into   six 
groups,  viz.  : 

(A)  The  explanations  which  depend  upon  the  facility  of 
external  motions  of  the  limbs. 

Advanced  by  Durand,  1881-2 ;  Peckham,  1886 ;  Clap- 
ham,  1894-5;  List,  1901;  Wilks,  1902;  Wray,  1903. 

(B)  Those  which  place  emphasis  upon  the  facility  of  cen- 
trifugal motions  of  the  limbs,   but  in  addition  attribute  the 
ultimate  causation  of  specific  movements  to  bilateral  representa- 
tion on  the  cerebral  cortices. 

Advanced  by  Erlenmeyer,  1879;  Ireland,  1881-1893; 
Leichtenstern,  1892 ;  Acker,  1894 ;  Mills,  1894 ;  Kingman, 
1905 ;  Buchanan,  1908. 

(C)  Those  hypotheses  based  primarily  upon  bilateral  rep- 
resentation on  the  cerebral  cortices.    This  group  is  closely  allied 
to  group  B. 

Advanced  by  Peretti,  1882;  Bianchi,  1883;  Bruce, 
1895;  Bastian,  1898;  Campbell,  1903;  Rudolf,  1903; 
Auden,  1909 ;  Burr  and  Crow,  1913. 

(D)  Those  that  admit  but  a  single  writing  centre. 
Advanced  by  Smith,  1879 ;  Allen,  1896 ;  Elder,  1897 ; 

Russell,  1900 ;  Jones,  1903. 

(E)  Those  that  depend  upon  disturbance  of  vision  or  of 
the  visual  centre. 

Advanced  by  Sweeney,  1900;  Hale  and  Kuh,  1901; 
Pendred,  1908. 
(P)     Those  which  recognize  various  controlling  factors  for 


1916]  Fuller:  Mirror-Writing  215 

individual    voluntary    reversals.      Thus    the    movements    may 
depend  upon  motor,  visual,  mental  or  auditory-motor  imagery. 
Advanced  by  Abt,  1901 ;  Downey,  1908. 

A  closer  examination  of  the  relative  value  of  these  groups, 
as  well  as  any  criticism  of  them,  may  be  best  postponed  until 
my  own  experiments  and  observations  have  been  given. 


PART  II 
EXPERIMENTAL  FINDINGS 

I  have  arranged  the  following  account  of  my  own  experi- 
ments to  conform  in  a  general  way  to  the  degree  in  which  the 
conditions  favored  the  production  of  mirror-writing.  A  fuller 
description  of  the  relation  of  these  conditions  to  mirror-writing 
will  be  found  toward  the  end  of  Part  III. 

1.  HYPNOSIS  (4  subjects) 

These  subjects  were  normal,  but  were  tested  when  in  the 
deeper  stages  of  hypnotic  sleep. 

Subject  A.  Twenty-nine  trials  writing  single  simple  words 
with  the  left  hand.  Of  these  words,  twenty-four  were  entirely 
reversed.  Thirty-four  trials,  single  letters,  twenty-eight  were 
entirely  reversed.  Of  the  six  that  were  not  completely  reversed, 
five  were  partially  reversed. 

Subject  B.  Thirty-one  trials  with  words,  seven  trials  with 
sentences,  thirty-nine  trials  with  letters.  Each  and  every  one 
was  reversed.  The  subject  showed  no  hesitation  whatever;  the 
reversals  were  easily  and  rapidly  written.  During  this  test, 
the  subject  was  hypnotized  four  separate  times,  at  periods  of 
from  one  to  two  weeks  apart,  and  each  time  produced  mirror- 
writing  post-hypnotically  as  well  as  while  hypnotized.  Accord- 
ing to  her  statement,  she  has  never  been  inclined  to  left-handed- 
ness.  She  was  unable  to  decipher  the  writing,  unless  by  the 
usual  means  of  retracing  each  separate  letter.  After  the  four 
tests,  I  explained  the  matter  of  mirror-writing  to  her.  Then, 


216     University  of  California  Publications  in  Psychology  tVoL-  2 

using  a  planchette,  I  desired  the  subject  to  devote  her  entire 
attention  to  the  problem  of  mirror-writing.*  The  result  was  a 
slow,  hesitating,  poorly  executed  form  of  reversal,  typical  of 
what  will  later  be  described  as  attentive  mirror-writing,  t  I 
then  carried  the  subject  through  successive  stages  of  dis- 
•  traction  of  the  attention  from  the  left  hand,  and  of  dis- 
sociation of  the  mental  from  the  motor  functions,  until  she 
arrived  at  that  stage  of  abstraction  so  nearly  allied  to  hypnosis 
that  the  mirror-writing  was  automatic  and  complete.  In  each 
successive  stage,  the  automatic  character  of  the  reversed  writing- 
showed  a  corresponding  increase.  As  an  example :  the  subject 
tapped  with  her  right  hand  with  the  greatest  possible  rapidity 
on  a  telegraph  key,  at  the  same  time  that  she  said  the  alphabet 
backwards  and  wrote  words  with  the  left  hand.  Several  words 
would  be  written  in  a  rightward  direction,  then  one  or  two  or 
three  would  be  reversed  directly  back  over  the  words  just  writ- 
ten. No  hesitation  occurred  between  the  two  styles,  and  the 
reversed  writing  was  quite  as  rapid  and  was  better  executed. 

Subject  C  responded  in  only  a  slightly  less  degree  than  did 
subject  B. 

Subject  D.  None  of  forty  words  was  reversed.  By  using 
various  suggestions  to  the  effect  that  the  automatic  and 
attentive  apparatus  should  be  dissociated,  I  succeeded  in  gain- 
ing a  complete  mirror  style  from  the  reagent's  left  hand;  after 
this  the  subject  was  just  as  amenable  to  the  different  tests  as 
was  subject  B. 

2.  HYSTERIA  (1  subject) 

Accompanying  the  other  symptoms  of  the  disease,  there  was 
complete  anesthesia  of  the  left  side  of  the  body — shoulder,  arm, 
and  pectoral  region.  I  placed  her  left  arm  on  the  planchette 


*The  planchette,  on  a  large  piece  of  paper,  I  found  most  useful  in 
many  tests.  A  minimal  amount  of  attention  need  be  directed  to  hold- 
ing the  pencil,  and  to  its  position  on  the  sheet;  moreover,  muscular 
weariness  in  prolonged  tests  is  reduced.  The  result  is  that  muscular 
responses  to  feeble  stimuli  are  much  more  marked. 

tSee  p.  241. 


1916]  Fuller:  Mirror-Writing  217 

but  obtained  no  response.  Upon  suggestion  that  it  was  the  right 
arm  which  rested  on  the  planchette,  and  that  she  could  write 
just  as  well  with  the  left  arm,  etc.,  I  finally  succeeded  in  get- 
ting writing  from  the  left  arm,  though  the  patient  was  unaware 
of  the  movement  of  the  arm.  The  writing  was  entirely  mirror- 
fashion. 

3.  DRUGS  (25  subjects) 

I  thought  that,  by  the  use  of  drugs,  I  might  simulate  to 
some  extent  the  conditions  which  are  most  favorable  to  mirror- 
writing  with  the  left  hand. 

a.  Alcohol  (18  subjects)* 

The  first  portion  of  the  test  was  the  same  in  every  case. 
It  consisted  in  holding  the  patient's  right  arm,  and  forcing  him 
to  write,  or  to  make  the  motions  of  writing,  with  the  left.  The 
process  was  accomplished  as  quickly  as  possible,  giving  the 
patient  very  little  time  to  collect  his  wits  or  to  plan  his  motions. 
Ten  trials  were  taken  with  an  interval  of  two  minutes  between 
each.  One  subject,  E,  deeply  influenced  by  the  drug,  wrote 
letters,  words,  and  entire  lines  in  mirror-writing. 

Four  patients  were  in  a  comatose  condition  and  were  exam- 
ined immediately  upon  revival  by  aromatic  spirits  of  ammonia. 
Two  of  them,  F  and  G,  indicated  that  they  would  write  (i.  e., 
made  definite  writing  motions,  which  could  not  be  recorded 
owing  to  the  conditions  of  the  tests)  exclusively  in  a  reversed 
direction;  one  (H)  indicated  a  reversed  direction  in  about  fifty 
per  cent  of  his  movements;  and  another  (I)  showed  no  tendency 
to  reversal,  aside  from  the  purely  random  nature  of  many  of  his 
motions. 

The  remaining  thirteen  reagents  were  less  completely  under 
the  influence  of  alcohol.  Eight  of  these  (grouped  as  J)  evinced 
considerable  doubt  and  usually  showed  a  tendency  to  stop  and 
figure  the  thing  out.  Prodded  on  to  the  attempt,  they  often 


*The  alcohol  was  not  administered  for  these  experiments.     Subjects 
were  found  in  various  localities  and  were  tested  on  the  spot. 


218     University  of  California  Publications  in  Psychology  tv°L-  2 

showed  impatience  and  dashed  off  their  word  now  rightward 
and  again  leftward.  The  greater  the  anger  and  haste  evinced, 
the  more  likely  was  the  writing  to  be  reversed.  The  other  five 
(grouped  as  K),  though  well  intoxicated,  were  less  so  than 
group  J.  They  showed  very  little  tendency  to  reverse  their 
writing,  and  then  only  when  they  could  be  forced  to  write  imme- 
diately after  the  signal  was  given. 

The  second  part  of  the  experiments  with  alcoholics  was  sub- 
ject to  much  variation,  as  one  plan  or  another  suggested  itself 
and  was  tried  out.  Thus,  suggestion  in  one  form  or  another 
was  tried  in  each  case.  By  this  means  the  percentage  of 
reversals  was  increased,  especially  in  the  relatively  less  intox- 
icated stages.  Two  of  group  J  and  one  of  group  K  became  so 
adept,  with  a  little  instruction,  that  it  seemed  quite  impossible 
for  them  to  write  rightward. 

&.  Cannabis  Indica  (3  subjects) 

Subject  L  (myself).  In  122  trials  at  writing  words,  seventy- 
two  per  cent  were  completely  reversed.  In  240  trials  at  writing 
individual  letters,  the  letters  were  completely  reversed,  or  hesita- 
tion was  shown  as  to  how  to  begin  the  letter,  or  the  letter  was 
reversed  in  part,  in  eighty-one  per  cent  of  the  cases. 

Subject  M.  Of  eighty-one  trials  at  writing  words  eighty- 
four  per  cent  were  completely  reversed.  Of  106  trials  at  writing 
individual  letters,  the  letters  were  completely  reversed  in  sixty- 
six  per  cent  of  the  trials;  hesitation  was  shown  as  to  beginning 
the  letter  in  six  per  cent  of  the  trials;  and  the  letter  was 
reversed  in  part  in  three  per  cent  of  the  trials. 

Subject  N.  In  ninety-six  trials  at  writing  words,  two  per 
cent  of  the  words  were  completely  reversed.  Of  145  trials  at 
writing  individual  letters,  three  per  cent  were  completely 
reversed;  hesitation  and  confusion  were  shown  in  twenty-nine 
per  cent  of  the  trials ;  and  the  letter  was  f ragmentarily  reversed 
in  thirteen  per  cent  of  the  trials. 

A  few  trials  at  right-handed  writing  were  given  in  each  case 


1916]  Fuller:  Mirror-Writing  219 

before  the  left-hand  tests  were  started.     In  no  case  was  there 
any  indication  of  reversal. 

As  usual,  after  the  regular  tests  were  finished,  variations 
were  added  in  the  attempt  to  locate  some  definite  factor  which 
would  either  favor  or  retard  the  production  of  mirror-writing. 
Here,  as  before,  suggestion  was  found  to  be  most  potent. 
Conversely,  merely  to  point  out  to  the  subject  the  queer  appear- 
ance of  his  reversed  script  was  enough  to  stop  altogether,  for 
the  time  being,  its  production. 

c.  Ether  (4  subjects) 

The  trials  are  necessarily  few  in  number  because  of  the  very 
short  duration  of  the  stage  of  intoxication  which  I  found  by 
testing  other  patients  to  be  most  favorable  to  mirror-writing. 
This  is  during  the  recovery  of  the  patient,  but  before  he  is 
conscious.  The  giving  of  the  drug  was,  of  course,  not  in  my 
hands,  as  the  patients  were  being  anaesthetized  for  minor  opera- 
tions. Usually  the  patient  merely  indicated,  by  a  jerky  sweep 
of  the  arm,  the  direction  of  his  writing.  With  the  right  arm, 
this  direction  was  always  rightward ;  with  the  left  arm : 

Subject  0.     Eight  trials,  words  all  reversed. 

In  twelve  trials  in  which  I  attempted  to  make  the  subject 
realize  his  error,  ninety-two  per  cent  of  his  movements  were 
reversed;  that  is,  this  patient  could  not  be  made  to  realize  that 
he  was  writing  in  any  but  the  normal  manner.  Later  stages 
in  his  recovery  were  not  satisfactory,  as  he  was  quite  conscioiis. 

Subject  P  made  no  reversals. 

Subject  Q  hesitated  before  each  motion,  and  only  in  two  of 
eleven  trials  did  he  reverse.  Single  letters  were  not  reversed  in 
nine  trials.  In  seven  of  thirteen  trials  he  was  induced  to  reverse 
words  or  letters  by  suggestions  to  that  effect. 

Subject  R  reversed  in  four  of  nine  trials  with  words ;  in 
six  of  eleven  trials  with  letters,  the  other  five  trials  showing 
doubt  and  no  motions  of  a  decisive  nature.  Suggestion  in  nine 
trials  produced  no  noticeable  increase  in  the  reversals. 


220     University  of  California  Publications  in  Psychology  [VoL-  2 

4.  ABSTRACTION   (15  subjects) 

The  persons  experimented  upon  were  in  normal  life,  ten 
belonging  to  no  particular  class,  while  five  were  engineering 
students.  Different  methods  of  inducing  abstraction  were  em- 
ployed; for  instance,  mental  arithmetic,  crystal-gazing,  and  so 
on.  In  half  the  trials  the  reagent  kept  in  his  left  hand  a  pencil 
held  on  paper  in  position  to  write;  and  in  an  equal  number  of 
tests  he  rested  his  left  hand  on  ^  planchette.  Immediately  upon  a 
signal,  he  was  to  begin  a  word.  I  found  that  only  the  first  line 
was  of  any  value,  for  almost  as  soon  as  they  began  to  write, 
they  awoke  from  their  abstraction,  and  summoned  attention  to 
their  aid  in  finishing  the  word.  The  first  stroke  was  started 
mirrorwise  in  some  thirty  per  cent  of  the  ninety  trials  I  deemed 
it  fair  to  accept  as  answering  all  the  conditions  of  the  test. 

5.  INSANE  (5  patients) 

These  patients  were  confined  in  an  institution,  and  no  hope 
was  felt  with  regard  to  their  recovery.  Unfortunately,  the 
diagnoses  of  the  particular  types  of  disorder  they  suffered  from 
were  not  satisfactorily  determined  for  inclusion  in  this  article. 

Subject  S  retained  just  enough  intelligence  to  write  a  few 
words.  He  looked  at  me  when  writing,  and  not  at  the  script. 
With  the  left  hand,  mirror-writing  was  formed  without  ex- 
ception. 

The  other  four  patients  wrote  mirrorwise  from  fourteen  to 
seventeen  per  cent  in  some  eighty-five  trials  each,  given  at 
intervals  of  several  days.  Hesitation  was  shown  in  starting  a 
letter  in  about  twenty-three  per  cent  of  eighty  trials  each. 

6.  HEMIPLEGIA  (right  side  paralyzed,  2  insane  patients) 

Subject  T  could  not  be  induced  to  write  in  anything  but  a 
reversed  direction.  His  general  mental  condition  was  so  poor 
that  he  could  remember  only  a  few  letters. 

The   other  patient  was  in  better  condition  mentally.     He 


1916]  Fuller:  Mirror -Writ  ing  221 

produced  mirror-writing  in  but  nine  per  cent  of  116  trials.  By 
suggestion,  I  could  raise  this  percentage  only  to  11  per  cent. 
Of  118  trials  with  individual  letters,  eight  per  cent  were  entirely 
mirrorwise,  ten  per  cent  showed  some  hesitation  or  fragmentary 
reversals.  That  is,  there  was  comparatively  little  hesitation; 
the  letter  was  either  reversed  or  it  was  not. 

7.  FEEBLE-MINDED  (69  patients) 

Of  these,  twenty-six  were  in  the  intermediate  grade  (second 
reader)  of  school.  Asked  to  write  their  names  with  the  left 
hand,  only  two  produced  mirror- writ  ing.  Directed  to  write  a 
double  word,  such  as  "Glen  Ellen",  with  the  left  hand,  but  to 
turn  the  paper  through  an  angle  of  180°  in  its  own  plane,  be- 
tween the  two  words,  I  found  that  six  wrote  '  *  Ellen ' '  in  mirror- 
writing,  including  the  two  above,  who  wrote  ' '  Glen ' '  mirrorwise 
as  well.  Eighteen  of  the  twenty-six*  showed,  in  all  the  tests, 
marked  confusion  in  starting;  the  line  now  being  started  mir- 
rorwise, and  then  in  its  usual  direction.  When  I  wrote  mirror- 
wise  the  word  "California",  but  three  of  the  patients  had  the 
slightest  difficulty  in  copying  the  word  reversed. 

Of  twenty-three  patients  in  the  advanced  grade  of  the  school, 
studying  geography,  etc.,  but  one  wrote  mirrorwise  with  the  left 
hand.  Testing  as  above  with  the  words  "Glen  Ellen",  but  three 
reversed  "Ellen".  Less  confusion  than  in  the  first  group  was 
shown  in  starting  a  letter  with  the  left  hand. 

Twenty  other  patients — nine  children,  eleven  adults — were 
tested;  these  were  of  low  grade,  and  not  in  the  school,  although 
they  could  write  a  few  words  or  letters.  One  half  were  chosen 
on  account  of  a  marked  neurotic  history ;  the  other  half  were  as 
free  from  anything  but  pure  " f eeble-mindedness "  as  I  could 
find.  Of  the  first  ten,  six  proved  to  be  mirror-writers,  two  of 
the  remaining  four  could  be  confused  into  mirror-writing,  while 
the  other  two  could  not  be  induced  to  write  mirrorwise  at  all. 
Of  the  last  ten,  but  one  wrote  mirrorwise,  only  two  could  be 
confused,  but  all  of  them  could  copy,  in  reverse,  words  written 
in  mirror  style. 


222     University  of  California  Publications  in  Psychology  CV°L-  2 

In  examining  the  histories  of  the  forty-nine  school  patients, 
I  found  that  with  three  exceptions,  every  patient  who  had 
shown  a  tendency  to  mirror-writing  had  a  neurotic  taint  other 
than  feeble-mindedness.  Thus,  one  had  epilepsy;  another,  a 
hysterical  mother;  another,  an  insane  father;  and  so  on.  Of 
the  remaining  patients,  one-fifth  gave  a  similar  history,  the  rest 
being  classified  as  merely  "feeble-minded"  or  retarded.  The 
neurotic  tendency  would  lead  to  mental  confusion,  whereas  the 
feeble-mindedness  would  place  the  patient  in  the  same  class  as 
young  normal  children.  This,  as  will  be  seen  later,  is  an  im- 
portant point  in  the  problem  of  mirror-writing. 

8.  DEAF  AND  DUMB  (77  patients)* 

Of  forty-two  in  the  upper  grades  in  the  school  examined, 
but  two  wrote  mirrorwise  with  the  left  hand.  Twelve  of  this 
number,  exclusive  of  the  two  above,  wrote  the  second  word  mir- 
rorwise upon  turning  the  paper  through  an  angle  of  180° 
in  its  own  plane.  Thirty-five  showed  great  readiness  in  copy- 
ing .words  after  I  had  written  them  mirrorwise. 

Of  thirty-five  deaf  and  dumb  children  in  the  lower  grades, 
none  showed  the  slightest  desire  to  reverse  letters  or  words. 
After  a  few  trials,  some  of  the  children  could  be  confused  on 
such  letters  as  S  and  N.  When  asked  to  copy  words  written 
mirror-fashion,  the  majority  were  able  to  do  so,  but  a  few  began 
at  the  left  and  copied  rightward. 

9.  BLIND  (5  subjects) 

I  was  inclined  to  doubt  Soltmann's  figures  for  the  deaf  and 
dumb,  but  thought  they  might  agree  more  nearly  with  the  left- 
hand  writing  of  the  blind.  Unfortunately  for  my  purpose,  blind 
children  are  no  longer  taught  to  write  long-hand,  and  I  could 
find  in  the  institution  I  visited  but  five  children  who  could 


*These  tests  on  the  deaf  and  dumb  were  made  to  verify  a  statement 
of  Soltmann,  quoted  by  Gould  28  p.  106  that  of  seventy-seven  deaf 
mutes,  thirty-five  per  cent  wrote  mirror-style  with  the  left  hand. 


1916]  Fuller:  Mirror-Writing  223 

write.  None  of  these  evinced  the  slightest  inclination  to  spon- 
taneous left-hand  reversals;  nor  could  they  be  readily  made  to 
understand  the  usual  explanation  of  mirror-writing,  or  to 
reverse  their  script.  It  should  be  understood  that  none  of  these 
five  children  was  congenitally  blind ;  with  the  cpngenitally  blind 
a  different  set  of  factors  might  be  operative,  making  left-handed 
reversals  easier. 

10.  NORMAL  CHILDREN  (26  subjects) 

First  type,  eighteen  children  who  had  just  learned  their 
letters.  In  no  case,  by  any  of  the  ordinary  means,  could  I  get 
any  of  these  children  to  reverse  their  words,  or  even  the  .letters, 
except  that  in  rare  instances  they  reversed  such  confusing  letters 
as  S  and  N.  Often  there  was  hesitation,  but  nearly  always  the 
correctly  formed  letters  were  written. 

Eight  children,  a  grade  ahead  of  the  first  type,  frequently 
reversed  certain  confusing  letters  and  figures  with  the  left  hand. 
By  employing  various  means  to  confuse  them,  this  percentage 
could  be  considerably  increased,  and  in  one  instance  I  succeeded, 
without  suggestion,  in  getting  several  words  in  mirror-style. 

11.  PERSONS  WITH  SPECIAL  TRAINING  OF  THE  ARMS 

Thinking  that  a  person's  occupation  or  his  training  in  writ- 
ing would  have  some  bearing  on  the  readiness  with  which  the 
motions  of  the  left  hand  would  be  reversed,  I  tried  a  number  of 
tests,  among  which  the  following  had  the  most  instructive 
results.  In  the  first  part  of  each  of  these  tests,  nothing  was 
explained  to  the  reagents,  who  were  merely  asked  to  write  the 
same  things  on  a  black-board,  simultaneously  with  both  hands, 
and  centering  the  attention  on  the  right  hand. 

a.  Clerks  (12  subjects) 

Analogous  accompanying  movements  based  on  the  visual  or 
mental  significance  of  the  symbols  was  best  illustrated  by  twelve 
clerks,  highly  trained  in  writing.  With  the  left  hand,  the  writ- 


224     University  of  California  Publications  in  Psychology  CV°L-  2 

ing  direction  was  always  rightward;  no  indication  of  reversals 
in  fifty-eight  trials.  When  the  same  reagents  were  urged  to 
rapidity,  one  subject  fragmentarily  reversed  three  letters  in 
thirty-two  trials. 

I  carefully  instructed  them  in  the  trick  of  mirror- writing. 
If  given  plenty  of  time,  they  could  reverse  the  characters  with 
the  left  hand,  but  if  urged  to  speed,  in  almost  every  instance 
they  wrote  rightward  with  the  left  hand.  After  some  twenty 
trials,  three  of  the  reagents  thought  the  mirror  form  the  easier. 
But  when  I  asked  these  three  to  write  mirror-fashion  with  only 
the  left  hand  active,  they  were  in  each  case  lost.  They  hesi- 
tated, made  two  or  three  false  starts,  and  finally  produced  a 
reversed  script  that  was  very  much  poorer  and  more  labored  than 
when  both  hands  were  active.  Asked  why  this  was  so,  each  one 
told  essentially  the  same  story;  that  he  thought  first  how  the 
motions  of  forming  the  ordinary  letter  would  look,  while  at  the 
same  time,  or  a  little  later  in  the  case  of  simpler  letters,  the 
hand  was  engaged  in  moving  in  just  the  opposite  direction. 
Sometimes,  with  certain  letters,  the  first  step  seemed  unneces- 
sary, whereas,  when  both  hands  were  active,  little  or  no  atten- 
tion was  given  to  the  left  hand.  The  other  nine,  after  consid- 
erably more  practice,  arrived  at  the  same  conclusion. 

Z>.  Plasterers  (12  subjects) 

Analogous  accompanying  movements  based  on  motor  habit 
was  best  illustrated  by  twelve  plasterers — whose  trade  requires 
that  both  hands  make  similar  movements  simultaneously.  They 
drew  on  a  black-board  any  figures  that  occurred  to  them,  also 
copied  several  figures  more  or  less  meaningless,  and  followed 
the  motion  I  made  when  drawing  other  figures.  As  usual  the 
subject  was  at  first  unaware  of  the  purpose  of  the  request.  In 

all  cases  the  left  gave  a  correct  imitation  of 

,v    /          \    \ 

the  right  hand,  i.  e.,  the  figures  were :  ,<   Jt         if  •  A. 

Subjected  to  the  same  tests  as  the  clerks,  they  were  more 


1916]  Fuller:  Mirror-Writing  225 

backward  in  learning,  probably  because  they  had  less  imagi- 
nation. On  the  other  hand,  the  clerks  and  students  found  it 
much  easier  to  draw  arbitrary  figures  similarly  related,  i.  e., 
than  did  the  plasterers,  after  this  problem 
had  been  set  them.  In  fact,  several  of  the 
students  drew  figures  in  both  relations  before  any  definite  direc- 
tion had  been  given. 


it 

\  A 


12.  UNIVERSITY  STUDENTS  (31  subjects) 

Merely  asked  to  write  simultaneously  with  both  hands,  they 
gave  no  indication  of  mirror-writing.  I  now  told  them  imper- 
fectly what  might  be  expected,  merely  giving  them  a  hint;  I 
then  asked  them  to  close  their  eyes,  and  to  write  rapidly  with 
both  hands.  Six  showed  a  rather  strong  tendency  to  reverse  the 
left-hand  figures.  It  is  significant  that  all  of  them  reversed  a 
few  lines,  mostly  the  first  strokes  of  the  figures.  About  a  dozen 
trials  each  were  given.  Furthermore,  this  ratio  more  than 
doubled  when  the  reagent  was  placed  in  a  condition  of  abstrac- 
tion (mental  problem,  etc.)  When  I  finally  explained  that  it 
was  easy  to  reverse  the  left-hand  script,  every  subject  found  this 
so,  after  a  couple  of  trials.  They  also  found  it  much  easier  to 
reverse  the  left-hand  script  when  the  right  hand  was  passive, 
than  did  the  clerks.  They  found,  with  a  little  practice,  that  it 
was  much  easier  to  reverse  with  the  left  than  with  the  right 
hand,  each  being  used  separately. 

I  noted  in  all  the  above  reagents  that  if  both  hands  are 
active,  the  left-hand  figures  are  much  more  cramped,  are  less 
freely  executed  and  less  pleasing  to  the  eye  when  drawn  in  a 
rightward  direction  than  when  reversed.  Again,  after  the 
reagents  were  well  practiced,  as  a  rule  they  found  it  easy  to 
write  mirror-writing  with  the  right  hand,  when  attending  to  the 
left  hand,  which  wrote  rightward.  Any  peculiarity  of  the 
strokes,  or  their  relation  to  one  another  such  as  is  apt  to  occur 
when  we  use  the  left  hand  for  writing,  will  be  observed  in 
reverse  in  the  writing  by  the  right  hand. 


226     University  of  California  Publications  in  Psychology  [VOL-  2 

13.  REVERSED  VISUAL  FIELD  (16  students) 

I  employed  a  right-angled  prism  with  broad  faces,  which  by 
means  of  straps  could  be  adjusted  comfortably  before  one  of 
the  subject's  eyes,  the  other  being  blindfolded  by  a  curtain 
dropped  from  the  front  of  the  gear. 

Sixty-four  trials  at  writing  with  the  right  hand  produced  no 
evidence  of  reversals.  Sixty-eight  trials  at  writing  with  left 
hand — rightward  direction  in  eighty-seven  per  cent;  and 
scratches,  i.  e.,  starting  lines  in  one  direction  or  another,  and  as 
soon  discontinuing  them,  confusion,  and  inability  to  produce 
anything  like  rightward  or  reversed  writing,  in  thirteen  per 
cent.  Only  in  seven  of  the  above  sixteen  reagents  did  this  con- 
fusion occur. 

The  subject  was  then  asked  to  pay  particular  attention  to 
the  visual  appearance  of  the  writing.  With  the  right  hand,  this 
made  very  little  difference ;  the  reagent  was  apt  to  make  one  or 
two  false  starts,  but  in  no  case  was  a  complete  word  reversed; 
and  very  soon  he  struck  off  in  a  rightward  direction.  With  the 
left  hand,  however,  the  thirteen  per  cent  of  confusion  was  raised 
to  ninety-one  per  cent.  Only  after  the  subject  was  familiar 
with  the  apparatus  did  he  produce  anything  resembling  letters ; 
and  then  he  usually  guessed  the  purpose  of  the  experiment, 
making  further  results  of  little  or  no  value. 

Using  fourteen  students  who  were  unfamiliar  with  the 
apparatus,  I  attempted  to  find  the  percentage  of  meaningless 
figures  that  would  be  reversed.  The  tests  I  found  most  useful 
required  the  memorizing  of  a  series  of  five  figures  by  eye  alone ; 
the  subject  had  then  to  put  the  prism  before  the  eye  and  write 
off  the  figures  with  the  right  hand  and  then  the  left  hand,  with- 
out depending  upon  any  particular  control.  Then  I  would 
caution  the  reagent  to  depend  as  fully  as  possible  upon  his 
visual  remembrance  of  the  figures;  and  again,  upon  the  mus- 
cular remembrance.  The  next  series  involved  the  learning  of  a 
new  set  of  figures,  but  principally  by  drawing  them  over  and 
over  with  the  right  hand.  Then  after  adjusting  the  mask,  the 


1916J  Fuller:  Mirror-Writing  227 

tests  were  repeated  as  in  the  series  above.  A  third  series  was 
similar  to  the  above,  except  that  the  left  hand  was  the  active 
member  by  which  the  learning  was  accomplished. 

In  the  following  table  the  method  by  which  the  figures  were 
memorized  is  indicated  as  the  "series".  The  "control"  indi- 
cates the  sense  which  the  reagents  were  cautioned  to  depend 
upon.  The  first  column  of  figures  is  the  number  of  reagents, 
with,  in  the  second  column,  the  average  number  of  their  reversals 
in  every  twenty  trials. 

Some  additional  series  were  tried  in  which  the  learning  of 
the  figures  was  with  the  field  reversed,  and  the  test  was  with  a 
normal  field.  Except  that  the  reagents'  surprise  was  a  bit 
keener,  the  results  were  essentially  similar  to  those  of  the  series 
above. 

PART  III 
THE  EXPLANATION  OF  MIRROR-WRITING 

1.  THE  PHYSIOLOGICAL  FACTOR  IN  MIRROR- WRITING 

The  majority  of  authors  agree  that  there  is  present  in  the 
right  brain  a  centre  which  governs  left-handed  mirror-writing. 
Such  an  explanation  very  readily  is  suggested.  The  multiplicity 
of  interpretations  it  permits  allows  infinite  variation  to  accord 
with  many  diverse  aspects  of  isolated  cases.  Yet  I  can  not 
accept  this  theory  as  the  most  satisfactory  explanation.  I  hold 
that  a  single  "centre"  is  adequate  to  cause  all  of  the  manifes- 
tations of  reversed  writing.  The  very  elasticity  of  the  double- 
centre  theory  occasions  complications,  even  contraditions,  when 
one  attempts  to  correlate  all  the  cases  and  modified  explanations 
and  experimental  findings.  Again,  it  is  against  the  concepts  of 
modern  physiology  to  think  of  a  separate  graphic  centre — as 
such,  or  in  any  of  the  modified  or  reduced  forms  set  forth  by 
various  investigators  in  this  subject — as  located  in  the  right 
brain  of  right-handed  indviduals.  Also  consideration  of  experi- 
mental data  and  study  of  the  numerous  cases  reported  in  the 


228     University  of  California  Publications  in  Psychology  [VoL-  2 


RIGHT  HAND 

LEFT  HAND 

SERIES 

CONTROL 

Reagents 

Reversals 

Reagents 

Reversals 

Series  1 

General 

11 

0 

10 

0 

1 

12 

1 

16 

2 

4 

3 

12 

(Mem. 

by  eye) 

Visual 

8 

0 

3 

0 

1 

20 

4 

20 

2 

17 

3 

14 

2 

12 

3 

12 

1 

7 

1 

2 

13 

0 

3 

0 

Muscular                  1 

4 

2 

8 

9 

4 

13 

0 

8 

0 

Series  2 

General 

1 

6 

3 

12 

3 

8 

(Mem.  by 

right  hand) 

Visual 

12 

0 

3 

0 

.       1 

16 

9 

6 

1 

7 

2 

4 

13 

0 

4 

0 

1 

8 

3 

12 

Muscular 

6 

8 

1 

4 

Series  3 

General                  12 

0 

11 

0 

2 

4 

2 

8 

1 

4 

(Mem.  by 

left  hand) 

4 

0                       2 

0 

7 

10                      1 

20 

Visual 

2 

8 

9 

8 

1 

4 

2 

4 

Muscular 

11 

0 

11 

0 

1 

16 

1 

8 

2 

10 

2 

4 

1916]  Fuller:  Mirror-Writing  229 

literature,  has  led  me  to  believe  that  such  a  supposition  is 
not  necessary.*  Therefore  it  is  the  purpose  of  this  section  to 
explain  the  basic  motor  complex  which  enables  the  unpracticed 
left  hand  to  produce  a  skillful,  automatic  reversed  script. 

In  this  section,  I  shall  treat  only  of  this  physiological  aspect, 
and  not  of  the  psycho-physiological  whole,  which  will  be  reached 
only  at  the  end  of  the  next  section. 

As  an  observed  fact,  there  can  be  no  question  of  the  ability 
of  the  normal  man  to  execute  either  consciously  or  uncon- 
sciously associated  movements,  that  is,  symmetrical  accompany- 
ing movements.  As  I  have  already  noted,  the  exact  central 
complex  involved  in  such  movements  yet  remains  a  matter  of 
conjecture.  However,  I  should  feel  that  this  paper  were  incom- 
plete did  I  not  express  an  opinion  as  to  the  nature  of  what  is 
evidently  a  firm  organic  basis  for  these  movements. 

This  opinion  is,  that  in  every  instance  of  stimulation  of  a 
nerve  on  one  side  of  the  body  (primary  stimulus)  there  is,  by 
the  arrangement  of  the  central  paths,  opportunity  afforded  for 
stimulation  of  the  corresponding  nerve  on  the  opposite  side  of  the 
body  (secondary  stimulus).  It  will  thus  occur  that  the  graphic 
representation  of  the  secondary  stimulus  will  be  an  exact  mirror 
replica  of  the  graphic  appearance  of  the  primary  stimulus. 
Accordingly  all  symmetrical  movements  may  be  traced  ulti- 
mately to  a  single  brain  area.  From  this  area,  the  motor  com- 
plex of  the  side  primarily  intended  to  be  active  receives  its 
stimulus.  The  opposite  side  is  stimulated  to  a  lesser  degree  either 
by  its  direct  connection  with  the  primary  area;  or  indirectly 
by  its  connection  with  the  opposite  motor  complex;  probably 
both  means  are  available.  For  the  purpose  of  mirror-writing  it 
is  most  convenient  to  assume  the  truth  of  the  second  alterna- 
tive— that  the  connection  is  between  the  motor  cortices,  through 
the  corpus  callosum.  Evidence  in  favor  of  this  contention 
be  summarized  as  follows : 


*Unless,  of  course,  one  be  developed  by  practice  of  the  left  arm, 
which  is  evidently  not  the  case  in  spontaneous  left-handed  mirror- 
writing,  which  occurs  suddenly,  and  without  forethought  or  practice. 


230     University  of  California  Publications  in  Psychology  [VoL-  2 

(1)  In  the  first  place,  the  tendency  of  modern  physiology  is 
to  attribute  to  at  least  those  parts  of  the  brain  herein  consid- 
ered, the  function  of  an  "exchange  board"  rather  than  those  of 
a  * '  directing  monarch ' '. 

(2)  Muscular,  or  kinesthetic,  or  deep  sensibility  is  mediated 
by  the  rich  supply  of  afferent  (sensory)  nerves  distributed  to 
voluntary  muscles,  tendons,  ligaments  and  joints.    The  impulses 
carried  by  these  fibres  to  the  brain  are  necessary  for  the  proper 
contraction  of  a  muscle,  and  especially  for  any  co-ordinated 
movements.     Indeed,  section  of  the  posterior  spinal  roots  con- 
taining the  nerves  from  any  region  is  followed  by  a  loss  of  con- 
trol of  the  muscles  of  this  region  hardly  less  complete  than 
section  of  the  motor  roots.     The  muscles  are  withdrawn  from 
voluntary  control  in  spite  of  the  maintenance  of  their  normal 
motor  connections.32 

(3)  Within  the  central  nervous  system,  the  fibres  of  muscu- 
lar sense  in  part  pass  by  the  median  fillet  (sensory  decussation) 
to  the  cortex  of  the  opposite  side.     They  end  in  the  postcentral 
gyrus.     This  cortical  sensory  area  is  connected  by  association 
fibres  with  the  motor  areas  of  the  pre-Rolandic  convolution.   By 
this  arrangement,  a  reflex  arc  is  formed.     The  co-ordination  of 
this  arc  with  other  areas  is  necessary  for  the  act  of  writing,  as 
it  is  for  the  completion  of  any  voluntary  movement. 

(4)  When  voluntary  movement  is  undertaken,  there  must  be 
some  definite  condition  to  fulfill  or  satisfy  by  that  movement. 
It  makes  no  difference  if  the  condition  is  the  highly  co-ordinated 
act  of  writing,  or  if  it  is  some  relatively  simple  act,  such  as  a 
gesture.     The  ultimate  mechanism  is  identical.     One  becomes 
aware  that  a  certain  movement  should  be  made,  which  is  suf- 
ficient to  start  the  act.     Then  by  differences  in  the  deep  sensi- 
bility of  the  various  parts  affected,  and  co-ordination  of  ex- 
changes of  these  various  stimuli  in  the  brain,  we  get  the  move- 
ment completed. 

(5)  Let  us  suppose,  somewhat  schematically,  that  an  impulse 
is  sent  from  the  so-called  writing  center   (center  for  memory 
of  motions  entailed  in  formation  of  written  language)   which 


1916]  Fuller:  Mirror-Writing  231 

should  result  in  the  formation  of  a  letter.  Possibly  the  move- 
ment could  be  started,  but  even  at  its  birth  the  co-ordination 
would  be  snuffed  out,  and  random  movements  at  best  could 
follow,  unless  the  motor  area  is  stimulated  by  the  afferent  mus- 
cular sensations.  Sufficient  proof  of  this  phenomenon  is  afforded 
by  breaking  the  circle  on  the  sensory  side. 

Writing  is  the  sum  of  a  number  of  simple  signs.  For  in- 
stance, when  forming  the  letter  L  we  have  grown  accustomed 
to  certain  kinesthetic  sensations  resulting  from  a  downward 
and  outward  stroke.  These  sensations,  or  stimuli,  are  necessary 
for  an  external  expression  of  the  central  memory.  And.  an  L 
is  never  made  by  an  inward  stroke — which  gives  radically  dif- 
ferent muscular  sensations  from  an  outward  stroke.  When  the 
point  is  reached  where  the  horizontal  line  should  commence,  its 
direction  is  either  outward,  or  the  movement  stops,  whether  the 
left  or  right  arm  is  being  used.  By  virtue  of  this  assumption, 
reversed  writing  will  be  the  logical  result  of  a  left-handed 
attempt  at  written  speech.  For  only  this  style  will  afford  kines- 
thetic sensations  which  agree  with  the  usual  writing  of  the  right 
hand:  The  most  likely  inference  to  be  drawn  from  this  observa- 
tion is  the  participation  of  a  single  writing-centre  common  to 
ordinary  right-handed  writing  and  to  left-handed  mirror  writ- 
ing. The  motor  impulse  originates  in  this  single  writing-centre, 
and  is  transferred  either  through  the  motor  emissary  of  the 
left  cortex  to  the  motor  emissary  of  the  right  cortex,  or  directly 
to  the  motor  emissary  of  the  right  cortex.  The  former  seems 
more  probable  in  cases  where  there  is  no  lesion  of  the  left  cor- 
tex, by  analogy  to  more  general  cases  of  associated  movements. 
The  latter  must  be  admitted  as  a  possibility  to  account  foi  the 
transferrence  of  impulses  in  those  cases  where  there  is  a  lesion 
of  the  left  cortex  (right  hemiplegia)  ;  for  the  writing-centre, 
being  but  a  specialized  part  of  the  general  motor  apparatus,  may 
be  supposed  to  be  as  intimately  connected  (by  the  corpus  callo- 
sum)  with  the  opposite  motor  cortex  as  is  the  general  motor 
cortex. 

Or  we  may  approach  the  question  in  another  way.    The  fact 


232     University  of  California  Publications  in  Psychology  CVoL-  2 

itself  of  the  rich,  commissural  connection  of  the  two  motor  cor- 
tices would  tend  to  detract  from  the  hypothesis  of  the  additional 
centre,  by  lessening  the  necessity  for  its  formation.  We  will 
consider,  first,  that  the  greatest  tendency  for  the  hands  to  move 
sympathetically  with  rhythmic  motions  is  in  involuntary  move- 
ments.*39 27  66  Second,  the  tendency  is  only  slightly  less- 
ened when  one  hand  follows  involuntarily  the  conscious  (but 
random)  movements  of  the  other.  Third,  most  conscious  move- 
ments are  not  accompanied  by  a  visible  muscular  contraction  of 
the  opposite  part.  Although  the  crossed  innervations  do  not 
function,  they  are  nevertheless  potentially  emitted  by  the  ulti- 
mate motor  source  of  the  movement  with  only  functional  dimu- 
nition  of  power,  as  is  demonstrable.  Instance  the  ease  with 
which  associated  movements  may  be  consciously  made.  Fourth, 
'we  have  no  experimental  ground  for  supposing  these  simpler 
transmitted  movements  to  be  interrupted  at  any  place  before 
reaching  the  motor  area  of  the  opposite  side.  Quite  the  opposite 
is  indicated  by  the  difficulty  we  encounter  in  attempting  to  make 
synchronous  movements  which  do  not  correspond.  Fifth,  the 
simpler  impulses  being  crossed  by  such  a  direct  method,  it  be- 
comes needless  to  assume  the  far  more  cumbersome  complex  of 
an  added  station  so  complicated  in  nature  as  a  writing-centre. 
A  readier  appreciation  of  the  real  simplicity  of  mirror-writ  - 


*In  this  connection,  I  cannot  refrain  from  mentioning  a  few  primi- 
tive examples  of  symmetrical  accompanying  movements.  When  the 
corpus  collosum  is  directly  stimulated  from  above,  symmetrical  move- 
ment on  the  two  sides  of  the  body  may  be  obtained.  Another  inter- 
esting illustration  is  given  by  a  case  of  Kraft-Ebing's  [*2  p.  29].  The 
patient  is  hypnotized  and  a  figure,  as  K,  is  placed  on  one  side  of  the 
body  and  suggested  as  hot;  a  blister  is  raised  at  this  area,  and  also  a 
symmetrical  and  reversed  blister  on  the  opposite  side.  Yet  another 
example  is  found  in  the  "scratch  reflex",  "cross-extensor  reflex", 
etc.,  of  Sherrington.62  if  one  leg  of  a  dog,  for  instance,  be  stimulated, 
the  homonomous  leg  makes  scratching  movements,  while  the  opposite 
leg  presents  slight  steady  extension,  with  some  abduction.  Now,  the 
extension  is  a  protective  measure  to  support  the  animal  on  three  legs 
while  the  fourth  is  scratching.  We,  therefore,  have  abduction  common 
in  both  legs.  I  have  found  that  certain  variations  of  this  experiment, 
such  as  placing  the  animal  on  its  back  or  side,  may  result  in  faint 
scratching  movements  of  the  opposite  leg.  The  fact  that  here  we  deal 
with  an  overflow  spinal  reflex  in  no  whit  detracts  from  the  value  of 
the  analogy,  for  writing  itself  depends  upon  a  reflex  arc,  which  we 
may  suppose  to  be  connected  with  one  higher  centre,  as  here  indicated. 


1916]  Fuller:  Mirror-Writing  233 

ing  will  be  felt  only  by  grasping  the  similarity  between  uncon- 
scious corresponding  movements,  semi-voluntary  corresponding 
movements,  and  highly  complex  corresponding  movements,  as 
shown  by  the  above  brief  summary  of  observations  on  sympa- 
thetic motions.  That  is  to  say,  any  movement  of  one  side  of  the 
body  is  accompanied  by  a  potential  symmetrical  impulse  to  the 
corresponding  part  of  the  opposite  side.  This  is  a  physio- 
logical or  anatomical  provision.  The  functioning  strength 
of  the  impulse  varies  with  the  psychological  state  or  con- 
dition of  the  individual.  Thus  a  writer  has  only  to 
learn  the  knack  of  disengaging  and  occluding  the  stronger 
functioning  paths  and  letting  the  impulse  function  along 
the  weaker  paths,  to  have  the  usually  non-functioning 
impulse  result  in  a  skilled  movement  of  the  so-called  unpracticed 
side.  In  other  words,  the  table  is  turned,  and  the  one  system 
now  occupies  exactly  the  same  position  formerly  held  by  the 
other.  With  this  manipulation  fully  accomplished,  the  visible 
accompanying  movements  of  the  right  hand  become  unnecessary 
for  a  fluent  mirror-writing  by  the  left  hand.  With  a  lesser 
degree  of  dissociation  we  have  the  characteristic  mirror-writing 
that  occurs  in  simultaneous  writing  with  both  hands,  the  atten- 
tion being  directed  to  the  right  hand  while  the  left  hand  trails 
along  semi-automatically.  Or,  simpler  still,  writing  simulta- 
neously on  both  sides  of  a  sheet  held  in  front  of  the  body  and  in 
the  sagittal  plane. 

There  are  additional  objective  phenomena  confirmatory  of 
the  absence  of  the  secondary  centre.  Those  that  are  based  on 
synchronous  writing  are  so  easily  verified  that  I  need  scarcely 
more  than  mention  them  to  have  their  bearing  appreciated.  It 
is  easy  for  the  average  reagent  to  reverse  his  right-handed 
writing  if  his  attention  be  given  to  his  left  hand  while  this  left 
hand  is  forming  normal  writing.  All  the  peculiarities  and 
superfluous  stroke,  characteristically  made  by  the  left  hand  (e.  g. 


(.    (  fy  (  ig}  (  f/p  for  the  usual  right-handed  formation 

will  be  faithfully  copied  in  reverse  by  the  right  hand   (i.  e. 


234     University  of  California  Publications  in  Psychology  tv°L-  2 

r^  \  ^  '*  t*.  )*  VJ     )    Again,  it  is  practically  impossible  for  any 

reagent  that  I  have  dealt  with  to  write  different  letters  syn- 
chronously. •!  have  myself  attempted  this  repeatedly  but  have 
acquired  little  skill  in  the  performance. 

I  repeat  that  I  am  unable  absolutely  to  refute  the  possibility 
of  the  additional  centre  in  the  writing  complex.  I  have  there- 
fore collected  a  mass  of  evidence  both  for  and  against,  and  have 
formed  from  this  my  judgment.  Thus,  it  might  be  that  every 
movement  of  one  side  of  the  body  is  accompanied  not  only  by  a 
potential,  but  by  a  feeble  symmetrical  impulse  to  the  corre- 
sponding part  of  the  opposite  side.  By  constant  repetition,  as 
in  writing,  the  paths  conveying  these  impulses  would  become 
more  easily  traversible — paths,  in  fact,  that  would  be  denned 
in  exact  proportion  to  the  practice  of  the  functioning  side.*  In 
this  way  a  centre  might  become  sufficiently  formed  to  control 
left-hand  mirror-writing  in  case  of  lesion  of  the  left  brain.  Yet 
it  would  seem  that  even  if  such  a  supposition  were  tenable  the 
centre  need  not  be  located  in  the  right  brain,  since  symptoms 
of  apraxia  on  the  left  side  in  injuries  to  the  corpus  collosum 
have  been  reported,  in  which  there  was  no  lesion  of  the  right 
cortex  (32  p.  229).  Again,  it  is  usually  the  uneducated  right 
hemiplegic  who  resorts  to  mirror-writing.  Did  an  additional 
centre  control  left-handed  mirror-writing,  one  would  expect 
exactly  the  opposite,  for  the  centre  must  be  developed  in  exact 
proportion  to  the  practice  of  the  right  hand  at  ordinary  writing. 

It  seems  to  me  that  the  best  argument  for  the  bi-lateral  repre- 
sentation of  the  writing  centre  is  that  the  faculty  of  mirror- 
writing  has  in  rare  cases  been  suddenly  assumed  by  the  left 
hand  after  paralysis  of  the  right  hand  due  to  central  lesion. 
The  assumption  in  many  instances  has  been  that  the  central 
lesion  has  involved  and  destroyed  the  writing-centre  of  the  left 
hemisphere.  However,  there  is  some  doubt  cast  upon  the  loca- 
tion of  the  writing  centre  in  Broca's  convolution,  as  has  been 
shown  by  some  recent  work  by  Marie.  I  know  of  no  cases  of 


*See  footnote  on  page  246. 


1916]  Fuller:  Mirror-Writing  235 

mirror-writers,  where  to  conclude  from  post-mortem  findings, 
or  from  the  study  of  aphasics  or  hemiplegics,  that  the  writing 
centre,  as  such  has  been  destroyed  would  not  become  extremely 
hazardous. 

The  writing-centre  is  a  motor  memory  centre,  developed  by 
practice,  and  causing  the  formation  of  writing  to  be  an  auto- 
matic rather  than  an  attentively  controlled  process.  Yet  it  is 
never  so  automatic  as  even  such  complex  acts  as  reading  and 
speaking.  It  is  superior  to  the  motor  area  of  the  brain,  in  that 
the  motor  cortex  is  merely  the  emissary  area,  or  the  connection 
between  higher  centres  and  motor  nerves.  The  writing-centre 
was  originally  identical  with  these  higher,  intellectual  areas, 
but  has  become  in  a  sense  detached  from  them,  and  reduced  to 
a  unity  by  the  forces  operating  to  make  it.  a  physiologic  sending 
station,  requiring  the  least  possible  participation  of  the  higher 
centres.  Were  the  writing-centre  alone  destroyed,  the  patient 
might  again  learn  to  write  as  he  did  in  the  beginning.  Clearly, 
the  left-hand  writing  of  such  an  individual  would  not  be  mirror- 
wise  in  any  greater  proportion  of  cases  than  the  left-handed 
writing  of  the  perfectly  normal  right-handed  individual  or  of 
the  right-handed  child,  who  when  asked  to  write  with  the  left 
hand  scarcely  ever  reverses.  The  only  difference  between  this 
case  and  a  right  hemiplegia  supposed  to  involve  the  writing 
centre,  is  paralysis  of  the  arm.  And  in  fact  but  a  very  small 
proportion  of  right  hemiplegias  are  accompanied  by  mirror- 
writing.  These  cases  in  particular  have  been  cited  as  evidence 
of  destruction  of  the  left-brained  writing-centre.  But  then,  may 
one  not  ask  why  the  normal  individual  when  using  the  left  arm 
is  not  just  as  dependent  upon  the  centre  of  the  right  brain  as 
if  the  centre  of  the  left  brain  was  destroyed?  In  other  words, 
use  of  the  left  arm  should  imply  dependence  upon  the  opposite 
centre,  which  means  mirror-writing,  whether  or  no  the  centre 
for  the  right  hand  is  destroyed.  Should  the  use  of  the  right  leg 
be  preserved  in  a  hemiplegic  mirror-writer  and  the  patient  be 
unable  to  write  rightwards  fluently  and  automatically  with  this 
limb,  it  would  be  strong  presumptive  evidence  that  only  one  of 


236     University  of  California  Publications  in  Psychology  tv°L-  2 

two  writing-centres  was  destroyed,  but  I  have  never  heard  of 
such  a  case. 


C.  W.  S.     Centre   for   motor  memory   of  written   speech,   which   is 
identically  related   to  kinesthetic  sensations  from  either  side  of  the 
body,    those   from    the   left   arising   from    the   movements   of   mirror 
writing. 

M.    E.     Motor  emissary  of  left  cortex. 
M|.  Ei.    Motor  emissary  of  right  cortex. 

D.  L.     Decussation  of  lemniscus. 
D.    P.      Decussation  pyramid. 

a,  b,  c.  Graphic  demonstration  of  musculo-sensory  innervations  of 
right  arm,  which  are  correspondingly  related  to  a,-,  &i,  a,  of  the  left 
arm,  and  to  the  commissural  impulses  ait,  &ii,  ca. 


Fuller:  Mirror-Writing  237 

All  this  leads  to  the  conclusion  that  mere  paralysis  of  the 
right  arm  has  very  little  to  do  with  mirror-writing.  The  pre- 
sumption that  mirror-writing  depends  upon  the  retention  of  the 
single  writing-centre  is  therefore  more  logical  than  the  assump- 
tion of  an  additional  centre  to  account  for  reversed  writing. 

In  the  schema  on  p.  236  the  idea  embodied  in  the  above  dis- 
cussion is  summarized. 

For  the  motor  fulfillment  of  the  act  of  writing  we  may  sup- 
pose two  essential  steps :  the  first  and  lowest  is  the  simple  reflex 
arc,  involving  the  motor  areas ;  the  second  forms  the  connection 
between  the  writing-centre  and  the  reflex  arc.  In  associated 
movements  in  general,  the  primary  impulse  is  received  by  but 
one  motor  cortex.  From  here  a  secondary  impulse  is  trans- 
ferred to  the  motor  cortex  of  the  opposite  side.  Mirror-writing, 
being  but  a  specialized  instance  of  associated  movements,  may 
be  expected  to  follow  this  course.  Destruction  of  the  writing- 
centre  will  cause  a  loss  of  the  faculty  of  habitual,  or  automatic 
writing,  both  by  the  right  and  left  (mirroring)  hand;  but  does 
not  prevent  the  regaining  of  the  ability  to  write  by  again 
repracticing  the  art  with  either  hand. 


2.  THE  PSYCHOLOGICAL  FACTOR  IN  MIRROR- WRITING 

The  fundamental  physiological  relations  which  make  of  asso- 
ciated movements  the  simplest  response  to  a  bi-lateral  stimulus, 
points  to  the  validity  of  the  conclusion  of  Buchwald;13  Vogt;68 
Durand;21  Nicolle  and  Halipre;52  Ballet;6  Meige;49  Figuera;25 
Laprade44  and  many  others  cited  herein,  that  the  reversed  style 
is  the  normal  writing  of  the  left  hand.  May  one  not  ask,  then, 
why  mirror-writing  is  not  the  universal  style  followed  by  the 
left  hand?  Why  is  left-handed  reversed  writing  not  the  rule 
rather  than  the  exception?  Were  it  not  for  some  inhibiting 
influence,  one  would  expect  this  to  be  true  in  the  majority  of 
cases.  By  a  study  of  the  cases  adduced  in  the  literature,  I 
was  led  to  the  belief  that  this  inhibition  could  be  removed  bv 


238     University  of  California  Publications  in  Psychology  tv°L-  2 

experimental  methods.  The  nature  of  this  psychological  factor, 
and  its  relation  to  the  experiments  just  reported,  is  set  forth 
in  this  and  the  following  section. 

If  you  will  recall  the  example  of  the  letter  L    (given  on 
p.  231),  it  was  stated  that  the  horizontal  line  will  either  be 


Si        Connection  between  visual  area  and  motor  emissary  of  left 

brain. 
sa       Connection  between  visual  area  and  motor  emissary  of  right 

brain. 

d         Emissary  fibres  from  left  brain  to  right  arm. 
di        Commisural   connection   between   writing   centre   and   motor 

emissary  of  right  brain. 

da      Emissary  fibres  from  right  brain  to  left  arm. 
dm     Connection    between    the    association    area    and    the    motor 

emissary  of  right  brain. 

div      Connection  between  association  area  and  writing  centre. 
dv       Connection  between  visuo-psychic  and  association  area. 
V.  S.     Visuo-sensory. 
V.  P.     Visuo-psychic. 
A.  A.     Association  area. 
M.  E.     Motor  emissary  of  left  brain. 
C.  W.  S.     Center  for  written  speech. 
Mi.  E{.     Motor  emissary  of  right  brain. 


Modified  from  Lickley. 


Fuller:  Mirror-Writing  239 

continued  outward,  or  will  not  be  drawn.  The  latter  alterna- 
tive will  exist  only  if  the  former  process  is  interfered  with  by 
our  higher  conception  of  what  an  L  should  be,  i.  e.,  how  it 
should  appear  when  on  paper.  With  the  visual  significance 
of  the  anticipated  movement  as  guide,  the  line  will  certainly 
be  directed  inward,  supposing  that  the  left  arm  is  being  used. 
By  the  inclusion  of  this  element,  embracing  the  'visuo-psychic,' 
' visuo-sensory ',  and  'association'  areas,  the  provisional  diagram 
on  page  236  may  be  completed  as  in  the  figure  on  page  238, 
opposite. 

To  write  from  left  to  right  with  the  left  hand  implies  that 
the  activities  of  the  paths  SH,  diV,  d*,  dm,  (si,  di  are  in- 
volved in  the  process,  but  to  a  much  less  degree)  must  be 
abnormally  increased  to  the  complete  minimizing  of  the  grapho- 
motor  control  as  described  above.* 

Since  the  grapho-motor  control  is  the  simpler  and  physiolog- 
ical control,  and  is  provided  for  by  the  arrangement  of  the 
central  motor  complex,  I  maintain  that  rightward  writing  by 
the  arm  on  the  same  side  of  the  body  as  the  writing  centre,  is, 
usually!  of  the  character  of  drawing,  as  contrasted  with  that 
of  writing.  For  by  "writing"  I  understand  the  smooth,  easily 
flowing,  spontaneous,  nearly  automatic  series  of  movements 
which  through  training  follow  each  other  without  the  necessity 
of  direct  participation  of  the  conscious  or  intellectual  centres 
at  whose  instigation  the  process  originally  arose.  Entirely  the 
opposite  of  this  facile,  I  might  almost  say  unconscious,  sequence 
is  the  labored,  sometimes  painfully  conscious,  visually  super- 
vised and  poorly  executed  left-handed  rightward  "drawing". 


*See  Part  III,  Section  1,  pp.  227  ff. 

t"Usually"  refers  to  the  occasional  use  of  the  left  arm  (or  the  right 
arm  in  the  left-handed  individual),  to  distinguish  this  condition  from 
the  persistent  left-handed  rightward  writing  following  permanent 
injury  to  the  right  arm,  or  the  sensori-motor  arc,  and  in  which  there 
are  two  possibilities  for  the  writing  to  become  automatic:  first,  the 
gradual  formation  of  a  new  centre  under  the  influence  of  constant 
practice  controlled  by  the  visual  areas;  or,  second,  the  persistence  of 
the  more  complex  "drawing  paths",  including  the  participation  of  the 
old  writing-centre,  which  by  practice  becomes  semi-automatic.  The 
end  results  are  identical. 


240     University  of  California  Publications  in  Psychology  CV°L-  2 

The  impulse  from  the  grapho-motor  apparatus  which,  if  unre- 
stricted, would  cause  a  left-handed  mirror-writing,  suffers  by 
its  reversal;  by  the  addition  to  it  of  various  impulses  from  the 
visual  and  association  areas;  and  by  the  interference  with  the 
free  passage  of  the  impulses  occasioned  by  the  participation  of 
the  same  higher  centers  which  made  possible  the  birth  of  the 
writing  centre.  Conversely,  left-handed  reverse  "writing" 
would  occur  in  direct  proportion  to  the  degree  of  suppression  or 
inhibition  of  the  interfering  paths,  from  the  visual  and  associa- 
tion areas,  or — what  amounts  to  the  same  thing — with  the 
increasing  canalization  of  path  di. 

We  must  remember  that  the  visual  complex  predominates 
as  an  absolute  "control"  only  in  left-handed  left-to-right  writ- 
ing. Using  the  right  hand,  we  may  attempt  all  sorts  of  con- 
fusions on  the  visual  sensations,  but  they  will  never  usurp  control 
from  the  automatic  habitual  control  of  writing.  This  circum- 
stance is  well  known  by  the  following  experiment:  Place  the 
right  arm  on  the  desk  in  a  position  for  writing ;  then  curve  it 
inward,  at  the  same  time  throwing  the  shoulder  forward 
until  the  hand  points  toward  the  mid-sternal  line  of  the  body; 
a  completely  inverted  writing  will  now  be  found  far  more 
natural  than  writing  which  to  the  eye  appears  normal.  Only 
the  legibility  of  our  ordinary  writing  depends  to  a  very  great 
extent  upon  the  visual  stimulus.  Thus,  for  proper  spacing, 
for  alignment,  for  the  equality  of  letters,  to  avoid  losing  the 
way  when  in  the  midst  of  a  word  and  so  misspelling  it ;  in 
general,  for  purposes  of  orientation,  sight  is  quite  necessary.65 
But  this  direct  visual  guidance  may  be  dispensed  with,  although 
the  central  memory  and  the  sensori-motor  arc  are  indispensible. 
An  observation  of  no  little  significance  is  that  we  regard  the 
letters  just  written,  and  do  not  follow  the  movements  of  the 
fingers  or  of  the  pen  point  in  tracing  individual  signs.  Here 
is  the  most  obvious  distinction  between  the  external  visual  con- 
trol, and  the  "internal  writing",  as  it  has  been  termed.  The 
former  immediately  follows,  the  latter  immediately  precedes, 
the  writing  of  the  letter  (65  p.  61). 


1916J  Fuller:  Mirror-Writing  241 

There  is,  as  I  have  indicated,  one  type  of  mirror-writing 
which  is  purely  automatic.  For  obvious  reasons,  it  is  this  type 
of  mirror-writing  which  most  interests  us.  But  there  are  two 
other  controls  which  may  influence  one  to  a  reversed  writing. 
One  is  the  voluntary  visuo-muscular  transposition  of  the  motions 
made  in  forming  the  letters  in  reversed  form.  The  other  is  the 
confusion  of  the  lateral  relationships  of  objects  in  space.  These 
three  control  factors  may  be  combined  in  any  proportion ;  but 
each,  if  present  as  the  major  influence,  will  result  in  the  produc- 
tion of  a  type  of  mirrored  lettering  that  is  distinctive. 

The  second  type  of  control,  then,  occurs  when  one  voluntarily 
endeavors  to  reverse  his  writing.  If  the  condition  extended  no 
further  than  the  conscious  and  attentive  endeavor,  it  would 
have  little  to  do  with  my  problem,  which  is  concerned  primarily 
with  the  automatic  reversals  of  the  left  hand.  For  until  one 
gains  some  confidence  in  the  use  of  the  left  hand;  that  is,  until 
he  has  practiced  writing  somewhat  with  the  left  hand,  this 
attentive  form  of  reversal  may  be  executed  almost  as  well  with 
the  right  hand  itself.  However,  one  should  remember  that  here, 
as  in  every  instance  where  a  right-handed  individual  writes 
mirrorwise  with  the  left  hand  (or  vice  versa)  the  mechanical 
or  commissural  fibres  have  been  "trained"  by  the  practice  of 
the  right  hand.  As  one  practices  left-handed  intentional  mirror- 
writing,  he  feels  the  influence  of  this  factor  in  a  constantly 
increasing  degree.  He  soon  realizes  that  left-handed  mirror- 
writing  is  far  easier  than  right-handed  mirror-writing.  And 
before  long  he  regards  left-handed  mirror-writing  as  easier  than 
left-handed  rightward  writing ;  that  is,  the  mirror  style  requires 
less  attention,  and  is  therefore  more  freely  and  rapidly  written. 
However,  without  this  preliminary  practice  one  finds  it  practi- 
cally impossible  to  dissociate  what  I  have  termed  the  psycho- 
logical factor,  or  briefly,  the  attention,  without  the  use  of  such 
artificial  methods  as  are  described  (on  p.  215  ff.)  with  the  experi- 
mental relations.  But  when  such  devices  are  used,  the  mirror- 
writing  is  probably  no  longer  attentively  controlled,  but  is  of 
the  nature  of  an  automatic  reversal.  For  the  same  reason, 


242     University  of  California  Publications  in  Psychology  tv°L-  2 

attentive  or  intentional  left-handed  reversals  which  have  been 
practiced  are  to  be  regarded  as  having  passed  more  to  the 
automatic  class  of  control. 

This  may  be  of  interest,  in  that  a  possibility  is  suggested 
for  the  mode  of  origin  of  some  cases  of  pseudo-spontaneous 
mirror-writing.  It  does  not  seem  improbable  that  some  people, 
through  some  whim  would  practice  reversed  writing.  Finding 
this  the  most  satisfactory  style,  both  in  ease  and  quickness,  they 
might  persist  in  its  use  till  the  conscious  transposition  of  the 
images  became  unnecessary;  that  is,  until  the  process  has  been 
relegated  from  the  more  essentially  attentive  to  the  more  essen- 
tially automatic  systems ;  until,  in  a  word,  we  have  an  automatic 
reversal  acquired  through  practice,  which  step  is  usually 
omitted. 

The  third  type  of  control  for  reversed  writing  is  contrasted 
in  every  way  to  the  second  type;  it  is  due  to  confusion  of  the 
lateral  relationships,  and  is  for  this  reason  always  of  a  frag- 
mentary character  where  unassociated  with  the  other  controls. 
Hale  and  Kuh31  have  called  attention  to  the  fact  that  this 
type  of  reversal  is  almost  universal  with  the  right  hand  of  normal 
children  of  a  certain  age.  Considering  only  the  element  of 
confusion,  one  would  expect  that  the  proportion  of  reversals 
by  the  left  hand  would  be  slightly  higher  with  the  same  children, 
due  to  a  greater  disorder  experienced  in  writing  with  the  left 
hand  the  same  confusing  lines  that  are  so  often  misdirected 
under  the  more  favorable  conditions  of  right-handed  writing. 
We  must  not  fail  to  consider,  however,  that  as  left-handed 
reversals  are  always  aided  by  the  physiologically  crossed  motor- 
complex,  the  left  hand  is  more  prone  to  this,  as  to  other  types 
of  reversal.  If  this  process  of  confusion  be  exaggerated  suffi- 
ciently, the  influence  of  the  crossed  automatic  paths  in  contrast 
to  the  influence  of  the  paths  of  attentive  control  will  be  so 
great  that  the  fragmentary  left-handed  reversals  will  become 
complete,  and  a  true  automatic  mirror-writing  will  result. 

The  left-right  relations  of  objects  in  space  are  extremely 
elusive.  They  are  acquired  last  and  with  most  difficulty,  are 


Fuller:  Mirror-Writing  243 

hence  easily  confused  in  the  process  of  learning  and  are  the 
first  to  be  lost  in  a  process  of  spatial  degeneration.  Instances  to 
the  point  are  legion,  and  one  has  but  to  try  an  habitual  movement 
before  the  mirror,  or  to  watch  a  squad  of  recruits  in  facing 
movements  to  be  convinced.  On  the  other  hand,  above-below 
relations,  being  more  fundamental,  are  rarely  confused,  which 
would  explain  the  fact  that  spatial  confusions  of  writing  are 
so  seldom  those  of  fragmentary  inversions.  We  may  well  expect, 
then,  the  normal  right-handed  writing  of  children  at  a  certain 
stage  of  their  development  to  be  fragmentarily  reversed,  espe- 
cially such  confusing  letters  as  8  and  N.  Exactly  the  same 
incomplete  mastery  would  explain  the  fragmentary  reversals  of 
uncultured  adults.  Add  to  these  facts  the  condition  that  through 
some  (usually  central)  lesion  the  left  arm  must  be  used  by  an 
individual  who  is  strongly  of  motor  tendency,  and  we  need  not 
be  surprised  if  he  is  inclined  to  ignore  the  confusing,  purely 
sensory  relationships,  and  completely  reverse  his  script ;  i.  e.,  to 
rely  upon  the  habitual,  or  motor,  complex,  rather  than  upon 
the  intellectual  complex  of  writing. 

Conversely,  we  should  expect  the  educated  person,  with  his 
thoroughly  mastered  relations,  not  to  be  baffled  by  any  condition 
comparable  to  that  above.  But  what  might  ensue  if  this  indi- 
vidual (or,  as  well,  the  uncultivated  person)  should  combine 
aphasia  with  the  enforced  use  of  the  left  hand?  All  forms  of 
aphasia,  according  to  Marie,  are  due  to  interference  with  the 
posterior  association  area.  But  the  only  injury  that  can  cause 
pure  motor  aphasia  is  injury  to  the  lenticular  nucleus.  Motor 
aphasias  are  therefore  due  to  a  combination  of  cortical  injury 
in  the  posterior  association  area  (aphasia  proper)  and  a  sub- 
cortical  injury  (anarthria).  As  a  corollary  to  this,  aphasia  is 
always  associated  with  an  impairment  of  the  intellectual  powers. 
Now,  would  it  be  assuming  too  much  if  the  mirror-writing  which 
follows  hemiplegia  were  attributed  to  a  similar  circumstance? 
We  should  remember  that  mirror-writing  but  rarely  follows 
cases  of  hemiplegia  involving  the  left  hemisphere.  It  may  well 
be  that  the  lesion  in  these  exceptional  instances  is  essentially 


244     University  of  California  Publications  in  Psychology  [ VoL-  2 

similar  to  a  circumscribed  aphasia.  Or,  at  least,  the  lesion  might 
cause  disturbances  comparable  to  a  functional  dissociation  of 
the  attentive  from  the  automatic  controls.  Unfortunately,  I 
have  had  an  opportunity  of  studying  only  two  cases  of  hemi- 
plegics  who  could  write  at  all.  Both  of  these  patients  were 
confined  in  an  institution  for  the  insane.  It  would  be  unsafe 
to  draw  any  conclusions  from  the  fact  that  one  would  write, 
with  the  left  hand,  only  in  the  reversed  style,  though  the  analogy 
is  startling.  My  reasoning  is  therefore  entirely  a  priori. 

The  "normal"  or  "abnormal"  significance  of  mirror-writing 
forms  a  question  of  no  slight  importance.  In  attempting  to 
decide  it,  I  have  been  confronted  with  the  ambiguity  of  the  terms, 
which  are  apt  to  lead  to  some  confusion.  In  ordinary  writing, 
ideas  are  converted  into  the  form  of  words  which  are  transferred 
to  the  motor  system  and  expressed  as  written  speech.  But  writ- 
ing with  the  hand  not  accustomed  to  writing  is  a  novelty,  and 
as  such  brings  into  play  additional  elements  such  as  increased 
attention,  which  are  ordinarily  sufficient  to  influence  the  writing, 
in  order  that  it  may  be  legible  to  the  writer.  If  these  factors 
are  prevented  from  increasing,  or  are  reduced  below  the  level 
they  occupy  during  ordinary  writing,  the  crossed  motor  complex 
may  express  itself  in  the  form  of  mirror-writing  by  the  hand 
accustomed  to  writing.  However,  one  can  not  suppose  that  a 
novel  event  such  as  left-handed  writing  could  occur  normally 
uncombined  with  increased  attention,  unless  the  other  extreme 
— dissociation — is  reached.  The  fact  that  one  appreciates  this 
use  of  the  left  arm  as  something  new  or  unusual  focuses  his 
attention  at  once  upon  the  act.  If  not,  something  abnormal  is 
indicated.  And  the  attention,  we  found,  is  of  first  importance 
in  reducing  the  probability  of  a  reversed  script.  If,  however, 
because  of  the  presence  of  the  crossed  motor  complex,  we  agree 
that  mirror  writing  is  "normal"  to  the  left  hand,  we  must 
consider  the  inhibition  of  this  property  by  the  attention  as 
"abnormal".  Hence  the  answer  to  the  query  depends  upon 
which  of  the  processes  we  choose  to  call  the  "normal"  control. 

My  experience  has  led  me   to  consider  both  the   reversed 


1916 1  Fuller:  Mirror-Writing  245 

and  the  ordinary  script,  or  neither  of  them,  to  be  "normal" 
and  for  the  following  reasons : 

(1)  Mirror-writing  is  for  the  left  hand  the  simplest,  most 
direct,  and  essentially  the  automatic  motor  expression,  involving 
only  the  primary  central  motor  apparatus.    It  is,  therefore,  the 
"normal"  motor  automatic  script. 

(2)  But  the  fact  of  its   "abnormal"   appearance,   both  to 
the  eyes,  after  it  is  written,  and  to  the  perception  of  the  writer 
during  the  act,  makes  it  a  distinctly  "abnormal"  entity. 

(3)  Left-handed   rightward   script    will,    according   to   the 
above,  be  "normal"  for  the  higher  centers,  and  "abnormal" 
for  the  habitual  crossed  motor  apparatus. 

(4)  The  knack  of  mirror- writing  can  be  acquired  with  facil- 
ity by  anyone.     Yet  of  this  latent  power  the  vast  majority  of 
mankind  is  unaware.     But  one  may  not  argue  that  the  ease 
of  its  acquirement  constitutes  normality  for  a  process.    Nor  can 
we  suppose  that  the  rareness  of  a  thing  makes  it  abnormal.    We 
may  say,  however,  that  during  the  periods  of  acquirement,  we 
deal  with   an   "abnormal"   process,   which   becomes   "normal" 
when  the  higher  attentive  control  is  dissociated  with  ease  and 
habitually. 

(5)  There  can  be  no  doubt  of  the  normality  of  a  certain 
percentage  of  fragmentary  reversals  by  the  left  or  right  hand 
by  children  and  by  unlettered  adults.     The  confusion  of  the 
lateral   relationships   occurs   quite   naturally   in   the   course   of 
development.    They  are  more  "normal"  than  are  experimentally 
induced  reversals,  or  than  ' l  normally ' '  occurring  complete  rever- 
sals, because  the  dissociation  is  but  mementary,  is  less  complete, 
and  the  writer  is  unconscious  of  the  reversal,  at  least  until  after 
it  has  been  recorded. 

I  would  say  that  the  fundamental  perviousness  of  the  auto- 
matic as  against  the  attentive  paths  is  so  much  a  matter  of  indi- 
vidual idiosyncracy  that  no  line  may  be  drawn  between  the 
physiological  and  the  pathological.  The  one  extreme — namely, 
fragmentary  reversals  and  practiced,  intentional,  mirror-writing 
— is  clearly  perfectly  normal.  The  other  extreme — sudden, 


246     University  of  California  Publications  in  Psychology  [V°L-  2 

spontaneous,  complete  reversals — certainly  results  only  from 
organic  or  functional  lesions  having  the  nature  of  a  dissociation. 
While  the  apparatus  favoring  reversals  is  always  present  as  a 
physiologically  normal  entity,  yet  the  functioning  of  the  crossed 
impulses  indicates,  in  extreme  cases,  great  nervous  disorgan- 
ization. 

3.  EXPERIMENTAL  RELATIONS 

The  simplest  experimental  verification  for  my  argument  is 
the  ease  with  which  subjects  in  the  hypnotic  trance  may  be 
induced  to  write  mirror-wise.  Charlatans  have  frequently  taken 
advantage  of  so  evident  a  means  to  impress  their  audience  with 
the  supernatural  import  of  some  message.  Mediums  and  others 
have,  doubtless  in  all  good  faith,  placed  this  supernatural  inter- 
pretation on  their  accidental  left-handed  mirror-writing,  which 
is  apt  to  occur  in  auto-hypnotic  trance  states.  Special  directions 
are  not  generally  necessary,  aside  from  insisting  upon  a  left- 
handed  response.  Appropriate  suggestions  may  at  times  be  of 
aid;  for  instance,  the  subject  should  not  be  aware  that  he  is 
writing  in  any  but  the  normal  form.  And  why  is  hypnosis  a 
favorable — nay,  the  ideal — condition  for  reversed  writing?  The 
answer  is  at  once  that  the  response  of  the  automatic  mechanism 
is  more  completely  relieved  of  the  attentive  control  than  in  any 
other  condition.  The  diffused  activity  of  the  brain  is  limited. 
The  impulses,  being  confined  to  a  restricted  area,  tend  to  follow 
faint  "traces"  (i.  e.,  crossed  impulses  are  more  free  to  function) 
from  which  they  would  otherwise  become  deflected  (by  the 
attention)  were  the  content  of  consciousness  larger.  All ' ' paths", 
except  di  of  the  schema  on  p.  238  are  occluded  by  the  condi- 
tions of  the  experiment.  For  the  same  reason  the  "channel"  di 
is  "deepened  and  widened".*  The  writing  will  be  reversed 
because  of  the  identical  muscular  relation  between  it  and  normal 
writing  by  the  right  hand.  Ordinarily,  this  relation  is  disturbed 
by  the  interference  occasioned  from  the  visual  centre.  Ordi- 


*The   assumption  of   these  brain-conditions   is   supported   by    Rob- 
ertson.ss 


1916]  Fuller:  Mirror-Writing  247 

narily  therefore,  the  path  di  does  not  function  as  one  simple 
link  between  the  writing  centre  and  the  muscles  of  the  left  arm, 
similar  to  the  corresponding  link  for  the  right  arm. 

No  less  striking  is  the  effect  of  certain  drugs19  in  facilitating 
the  production  of  mirror-writing.  There  may  be  some  little 
difficulty  in  handling  a  person  sufficiently  influenced  by  the 
substances  for  our  purposes,  but  if  he  be  prevailed  upon  to 
write  at  all  with  his  left  hand  we  may  confidently  expect  at 
least  fragmentary  reversions.  Thus,  one  who  was  in  just  the 
proper  state  of  advanced  alcoholic  intoxication  refused  to 
move  his  left  arm  in  any  but  the  reversed  direction.*  Other 
subjects,  more  moderate  in  their  potations,  exhibited  lesser 
inclinations  to  reversals.  In  fact,  the  greater  number  of  any 
tests  indicated  a  direct  relation  between  the  degree  of  intoxica- 
tion and  the  extent  of  the  left-handed  reversed  responses. 
The  more  advanced  intoxication  favors  complete  reversals, 
while  in  the  less  complete  stages  of  intoxication  there  occur 
few  or  no  reversals,  even  of  a  fragmentary  character.  The 
most  satisfactory  stage,  all  considered,  is  one  in  which  the 
shifting  of  the  two  conditions  obtains.  One  may  see  beautiful 
illustrations  of  the  nice  balance  between  the  two  control  fac- 
tors that  this  state  favors;  at  one  moment  the  muscular  re- 
sponses are  mainly  governed  by  the  grapho-motor  stimuli ; 
the  next  moment,  the  patient  realizes  that  there  is  some- 
thing amiss  and  attempts  to  correct  the  error.  There  is  an 
instant  of  confusion  accompanied  by  random,  indefinite, 
motions  of  the  arm.  Then  the  subject  gathers  his  scattered 
wits,  concentrates  his  attention  upon  the  task  of  making  in- 
intelligible  signs,  and  for  a  longer  or  a  shorter  time  actually 
adheres  to  this  design. 

Ether  and  chloroform  t  present  essentially  the  same 
phenomena.  In  all  of  the  drug  tests  I  was  most  careful  to 
avoid  any  suggestions  which  might  lead  the  subject  to  suspect 
the  purpose  of  the  experiment,  as  the  mental  condition  under 


*See  p.  217. 
fSee  p.  219. 


248     University  of  California  Publications  in  Psychology  [y°L-  2 

these  drugs  is  one  which  lends  itself  readily  to  suggestion. 
These  drugs  are  all  narcotics.  As  such,  they  inhibit  the  pas- 
sage of  impulses  through  the  central  system,  the  formation 
of  associations  and  of  traces.  "Obviously",  says  Robertson58, 
"such  drugs  must  tend  to  limit  the  field  of  consciousness  to 
the  regions  most  vividly  stimulated  .  .  ."  What  could  be 
more  favorable  for  our  purpose  ?  By  inhibiting  the  passage  of  im- 
pulses, it  would  result  that  the  commissural  traces,  being  already 
formed,  in  however  slight  degree,  would  be  more  easily  tra- 
versed than  the  potential  link  with  the  visual  area.  The  forma- 
tion of  new  associations  is  more  essential  to  unpracticed  left- 
handed  rightward  writing  than  to  mirror-writing.  This  is  so 
apparent  as  not  to  need  comment,  I  think.  With  the  initial 
attempt  at  left-handed  centripetal  writing,  new  "traces"  must 
be  formed,  whereas  we  may  see  that  "traces"  conducive  to  left- 
handed  mirror- writing  exist  with  the  practice  of  the  right 
hand.  Lastly,  we  have  the  field  of  consciousness  limited  to  the 
left  arm  and  the  writing  mechanism,  i.  e.  the  endeavor  is 
notably  motor,  as  the  higher,  the  attentive,  fields  are  the  first 
to  be  depressed  by  the  drugs. 

The  action  of  Cannabis  Indica*  is  peculiar  to  our  problem. 
It  has  long  been  regarded  as  especially  facilitating  the  passage 
of  impulses  through  the  central  nervous  system.  If  one  were 
a  practiced  mirror-writer,  and  it  were  suggested  to  him  that  he 
should  use  only  this  style  with  the  left  hand,  then  mirror-writ- 
ing under  the  influence  of  this  drug  should  be  extremely  easy. 
This,  in  truth,  was  exactly  what  occurred  when  I  ate  the  hemp. 
But  an  entirely  different  set  of  influences  intervenes  if  the 
impulses  are  not  directed  into  the  mirror-writing  "paths"  by 
some  such  forces  as  those  operating  in  my  case.  The  activities 
of  the  higher,  attentive,  or  intellectual  parts  of  the  brain  are 
increased.  We  should  expect,  then,  to  have  the  "drawing" 
paths  for  the  left-handed  centripetal  writing  more  intimately 
connected  with  the  motor  area  of  the  right  cortex,  in  view  of 
the  fact  that  all  paths  are  more  easily  traversed.  However,  in 


*See  p.  218. 


1916]  Fuller:  Mirror-Writing  249 

the  two  cases  I  have  been  able  to  test,  I  gained,  in  one,  almost 
a  pure  mirror-style  with  the  left  hand.  The  other  showed  con- 
siderable confusion,  but  wrote  mirrorwise  in  but  a  small  per- 
centage of  trials.  No  doubt  the  explanation  lies  in  the  peculiar 
dissociative  action  of  Cannabis  Indica.  In  the  classical  descrip- 
tion of  the  action  of  the  drug70  the  individual's  attention  is  so 
occupied  in  observing  the  flights  of  his  imagination,  possibly 
revelling  in  the  visions,  or  in  analyzing  his  state  of  conscious- 
ness, that  the  motor  part  is  left  largely  unhindered  by  the 
usual  attentive  supervision.  My  hypothesis  is  that  under  pre- 
cisely these  conditions  there  .will  be  a  relatively  stronger  predi- 
lection towards  mirror-writing  than  towards  rightward  left- 
handed  writing. 

An  abrupt  transition  to  the  survey  of  the  less  evident  causes 
of  dissociation  is  instructive.  Perhaps  the  most  impressive 
example  of  this  sort  is  the  sudden  reversion  of  adults  which 
may  follow  functional  loss  of  the  right  arm.  Hemiplegias  have 
been  fruitful  in  calling  the  attention  of  observers  to  mirror- 
writing.  Instances  of  injury  to  the  right  arm  have  been  noticed 
to  precede  reversals.  Merely  intense  occupation  of  the  right 
arm  favors  synchronous  mirror-writing  with  the  left  arm.  Wit- 
ness the  case  of  the  telegrapher  who  often  jotted  down  messages 
with  his  left  hand,  while  tensely  operating  his  key  with  his 
right,  and  who  was  frequently  surprised  at  finding  the  written 
words  reversed.50  I  have  personally  questioned  forty  telegraph 
operators,  and  found  that  not  uncommonly,  under  similar  con- 
ditions, many  of  them  have  noticed  confusion  in  their  writing, 
though  not  all  of  them  were  sufficiently  interested  in  these  con- 
fusions to  remember  them  definitely  as  reversals.  Now  I  have 
found,  both  in  the  published  cases  and  by  personal  experience, 
that  there  is  a  direct  ratio  between  the  intellectual  control  and 
the  amount  of  dissociation  necessary  to  bring  about  mirror- 
writing.  If  one  glances  over  the  conditions  which  favor  the 
spontaneous  occurrence  of  mirror-writing*  he  will  observe  that 
there  is  supposed  either  a  low  grade  of  intelligence  or  a  disturb- 


*See  pp.  201-202. 


250     University  of  California  Publications  in  Psychology  CVoL-  2 

ance  of  the  higher  faculties.  And  this  we  might  expect,  for 
there  is  less  to  dissociate  in  the  unintelligent.  That  is  to  say, 
we  have  two  grades  of  intelligence  to  both  of  which  writing  is 
common,  and  both  of  which  possess,  therefore,  the  ability  to 
write  mirrorwise  with  the  left  hand.  The  circumstance  that  the 
left  arm  gains  in  skill  in  direct  ratio  to  the  practice  of  the 
opposite  arm,  i.  e.,  to  the  development  of  the  writing  centre  in 
the  left  cortex,  will,  of  course,  be  more  favorable  to  a  better 
mirror-writing  by  the  higher  intelligence.  But  this  is  rendered 
relatively  unimportant  by  the  greater  corresponding  increase  of 
the  psychological  content  and  training,  which  is  directly  antago- 
nistic to  mirror-writing.  There  will  be,  therefore,  a  greater 
number  of  conditions  favoring  an  unintelligent  mirror- writing. 
Conversely,  it  will  be  most  difficult  to  induce  the  highly 
educated  writer  to  reverse,  but  once  this  is  accomplished, 
the  reversals  will  be  much  more  legible,  complete,  uniform 
and  automatic.  This  is  apt  to  be  true  because  to  get  auto- 
matic left-handed  writing  at  all  we  must  attain  more  nearly 
that  ideal  property  of  dissociation  and  suggestion  which  is  most 
favorable  to  mirror-writing.  Whereas,  in  the  unintelligent  a 
much  lower  degree  of  dissociation  and  suggestion,  both  relatively 
and  absolutely,  will  suffice.  For  we  find  that  the  higher  we  go 
in  the  scale  of  intelligence,  the  more  is  the  purely  motor  expres- 
sion of  brain  activity  subordinated  to  some  form  of  expres- 
sion more  compatible  with  cultivation.  Mirror-writing  is  not 
ordinarily  a  thing  which  seems  to  intelligence  to  be  expressive 
of  beauty  or  usefulness,  and  is,  therefore,  unless  by  some  whim 
or  perversion,  not  tolerated. 

But  if  the  higher  intellectual  content  can  inhibit  mirror- 
writing,  then  a  reversed  vision  should  aid  in  the  production  of 
reversals,  for  vision  is  a  most  important  guide  to  motor  expres- 
sion of  the  psychic  areas.  However,  the  data  I  obtained  was 
absolutely  contrary  to  my  expectations.*  With  the  inhibiting 
visual  field  converted  into  a  support  of  the  commissural  paths, 
the  subject  ought  soon  to  orient  himself,  and  plunge  boldly  and 


*See  pp.  226-228. 


19163  Fuller:  Mirror-Writing  251 

naturally  into  centrifugal  writing  with  the  left  hand.  But  the 
reagents  calmly  ignored  the  visual  element,  and  wrote  cen- 
tripetally  with  the  left  hand;  and  when  they  attended  par- 
ticularly to  visual  control,  only  confusion  resulted,  with  nothing 
so  much  as  indicating  any  actual  progress  at  writing.  In  seek- 
ing for  an  explanation  of  these  phenomena,  which  at  the  time  of 
their  trial  apparently  so  completely  refuted  my  hypothesis,  I 
had  the  reagents  memorize  sets  of  simple  figures  and  then  repro- 
duce them  with  the  field  reversed.  A  marked  individuality  was 
shown  in  the  tendency  to  reverse  the  figures.  The  majority 
of  subjects,  however,  if  left  to  their  own  devices,  reversed  but 
few  or  none  of  the  figures,  even  with  oft-repeated  trials.  With 
the  right  hand,  reversals  were  extremely  rare;  and  when  they 
occurred,  they  showed  a  tendency  to  persist  after  the  prism  was 
removed.  That  is,  they  seemed  to  be  errors  of  memory  rather 
than  confusion  occasioned  by  the  reversed  visual  field.  Errors 
were  more  frequent  when  the  left  hand  was  used,  and  did  not 
show  a  corresponding  tendency  to  persist  after  the  removal  of 
the  prism  from  before  the  eyes. 

"We  may  infer  that  the  "muscular"  remembrance  of  the  right 
hand,  of  right-handed  individuals,  is  much  more  certain  or 
reliable  than  the  left.  Also  that  the  external  visual  element 
may  interfere  with,  confuse  or  control  the  movements  of  the  left 
hand  to  a  greater  extent  than  the  right.  But  the  latter  factor  is, 
after  all,  only  of  slight  import  to  the  motor  memory  complex, 
even  in  such  meaningless  figures  as  those  used.  The  confusing 
prism  aroused  the  subject's  attention,  warned  him  to  avoid  the 
unsafe  visual  influence  and  to  place  his  faith  in  the  more 
reliable  memory  impressions.  Muscular  action  is  in  imitation 
of  the  direction  of  the  thought.  Herein,  I  think,  lies  the  reason 
for  the  control  assumed  by  the  majority  of  subjects  in  volun- 
tarily reversing  their  left-handed  writing.  After  the  various 
tests,  I  had  every  suitable  subject  practice  this  style  of  script. 
The  majority  sooner  or  later  agreed  that  it  was  necessary  only 
to  keep  constantly  in  mind  the  necessity  for  reversing  the  let- 
ters, or  to  think  of  the  general  writing  direction,  or  to  start  a 


252     University  of  California  Publications  in  Psychology  [V°L-  2 

letter  in  a  reversed  manner,  to  have  the  hand  complete  the 
letter  with  little  or  no  attentive  guidance.  The  attentive  and 
the  grapho-motor  elements  were  working  hand  in  hand.  It  is 
but  another  step  to  suppose  that  without  sufficient  attention,  or 
with  the  proper  kind  of  confusion  of  the  attention,  the  grapho- 
motor  complex  may  take  charge  and  produce  a  left-handed 
reversed  script. 

In  the  writing  of  adults  with  the  left  hand,  I  see  a  process 
comparable  in  some  respects  to  a  certain  stage  in  the  history 
of  the  individual  acquisition  of  written  speech.  Where  a  child, 
for  instance,  has  just  thoroughly  learned  the  appearance  of  his 
letters,  he  devotes  extraordinary  attention  to  making  his  copy 
as  nearly  like  the  original  as  possible.  The  two  processes — the 
visual  appearance  of  the  letter,  and  the  tracing  of  a  likeness 
of  the  same  visual  form — are  so  closely  linked  together  as  to 
be  practically  a  unity.  I  carefully  studied  eighteen  such  children 
and  observed  some  forty  others  of  approximately  the  same  grade 
of  experience,  and  none  of  them  evinced  the  slightest  inclina- 
tion to  left-handed  reversals.  Nor  could  they  be  induced  to 
reverse;  confusion  and  return  to  the  usual  appearance  of  the 
letters  supervened  in  every  instance  that  reversing  was  tried. 
In  a  like  manner  the  adult  of  average  intelligence  thinks  it 
impossible  to  reverse  his  writing.  And  if  he  does  succeed,  he 
usually  calls  upon  his  greater  experience  to  reverse  the  mental 
image  of  the  visual  and  motor  " appearance"  of  the  writing. 

At  a  later  period,  the  child  shows  a  considerable  tendency 
to  become  careless.  Perhaps  his  joy  at  having  finally  mastered 
the  intricacies  of  graphic  language  incites  him  to  over-confi- 
dence in  his  ability  .to  write  invariably  a  correct  copy.  Prob- 
ably, too,  the  preponderating  visual  control  has  been  somewhat 
replaced  by  the  automatic  system  of  writing,  which  is  closely 
linked  on  the  motor  side  and  but  feebly  bonded  on  the  visual 
side.*  It  is  then  quite  easy  to  throw  the  child  off  his  guard, 
and  secure  whole  words  in  mirror  form.  I  found  in  a  prelim- 
inary study  of  eight  children  of  this  age  that  some  simple  sub- 


*See  pp.  238-241. 


1916]  Fuller:  Mirror-Writing  253 

terfuge  such  as  having  the  child  write  rapidly  two  closely  con- 
nected words,  for  instance,  "Berkeley,  California",  or  the  date, 
(but,  between  the  words,  having  the  paper  turned  rapidly  about 
through  an  angle  of  180°  in  its  own  plane),  was  often  sufficient 
to  cause  the  second  word  to  be  reversed.*  A  specialized  con- 
fusion is  aroused,  with  as  little  introduction  of  absolute  sugges- 
tion as  may  be. 

It  will  perhaps  be  advisable  to  consider  a  few  of  the  pub- 
lished cases  of  mirror-writers  which  may  not  seem  compatible 
with  my  argument.  Type  case:  E.  M.,  a  paralytic  imbecile 
girl  of  seven  years,  hemiplegic  since  birth;  when  learning  to 
write  with  the  left  hand,  she  persistently  produced  mirror- 
writing.38  Compare  such  cases  of  left-handed  children  learning 
to  write  with  the  interesting  report  of  Kingman.42  A  teacher 
injured  her  right  hand.  She  easily  wrote  mirror-wise  with  her 
left  hand  and  found  it  more  convenient  to  give  copy  to  her 
pupils  in  this  style  till  she  recovered.  The  children  used  a 
mirror  to  read  their  copy.  Three  of  these  children  were  exam- 
ined by  Kingman  and  found  capable  of  mirror-writing  with 
either  hand,  easily  and  rapidly.  There  is  a  ready  explanation 
for  these  occurrences  of  mirror-writers  quite  aside  from  the 
interpretations  that  might  be  drawn  from  the  consideration  of 
a  possibly  altered  central  motor  complex.  The  tendency  for 
children  to  mimic  the  motions  of  others  is  proverbial.  I  have 
had  occasion  to  observe  this  inclination  in  a  large  number  of 
cases.  The  average  child  will  blindly  follow  any  movement  of 
one  in  authority,  thinking,  no  doubt,  that  it  is  all  a  matter  of 
the  queer,  grown-up  idea  of  propriety,  to  be  adopted  without 
question  by  the  child.  This  is  especially  true  of  deaf  children, 
who  rely  more  upon  vision  and  who  are  more  apt  to  subordinate 
other  faculties  in  their  endeavor  to  follow  the  meaning  of  their 
instructor.  Even  more  would  this  be  true  in  the  imbecile 
attempting  to  imitate  obvious  graphic  signs  (65,  p.  83).  There 
have  been  cases  reported  where  defective  sight  was  associated 
with  the  mirror-writing  of  children.  In  one  instance,  upon 


*See  p.  223. 


254     University  of  California  Publications  in  Psychology  tv°L-  2 

removal  of  this  reflex  irritation,  the  writing  at  once  became 
rightward,  and  if  the  corrective  glasses  were  removed  the  writing 
was  again  mirrorwise.64 

Now,  the  centrifugal  direction,  being  the  biggest  and  most 
easily  grasped  feature  of  writing,  is  apt  to  be  seized  upon  first 
by  the  child,  especially  if  sentences  rather  than  letters  are  used. 
The  child  is  imitating  with  his  left  hand  a  series  of  motions  made 
by  the  right  hand  of  the  instructor.  Then,  too,  the  symbols 
which  the  instructor  forms  have  very  little  meaning  to  the  child 
who  is  just  learning  to  write,  hence  his  reversal  of  them  will 
have  little  or  none  of  the  unusual  in  their  appearance.  If  the 
child  is  allowed  to  continue  to  practice  the  reversed  form,  it 
will  become  habitual,  which  will  mean  merely  that  he  has 
learned  his  letters  in  reversed  form.  Ordinarily  this  process  is 
not  allowed  to  continue  to  such  an  extreme.  Occasionally  how- 
ever, this  does  occur,  as  is  shown  by  several  cases  where  reversed 
writing  could  be  quite  fluently  read.*  As  such  cases  are  able 
to  read  ordinary  writing,  it  would  seem  that  they  have  simply 
acquired  an  additional  alphabet-complex  in  their  reading-centre, 
by  which  they  are  enabled  to  interpret  mirror-writing.  It  is 
not  necessary  to  assume  a  visual  disarrangement  of  any  sort 
to  enable  one  to  read  mirror-writing,  since  all  who  are  able  to 
do  so  either  are  mirror-writers,  or  have  had  experience  with 
mirror-writing.  Without  this  experience,  which  must  be  quite 
extensive,  the  person  will  find  it  necessary  to  run  his  eye  back- 
ward over  a  word,  thus  deciphering  every  movement  as  it  was 
made  when  forming  each  letter. 

The  different  central  relations  that  might  be  noticed  in  the 
various  writing  combinations  of  the  left-handed,  and  various 
ambidextrous  tests,  form  a  tempting  subject.  But  this  is  a 
question  which  I  have  been  careful  to  avoid  as  beyond  the 
scope  of  my  problem.  At  best,  a  consideration  of  these  rela- 
tions could  but  lead  us  further  into  the  field  of  the  hypothetical. 
However,  I  may  mention  the  following  as  a  possible  explanation 


*Most    congenital    mirror-writers    can    read    reversed    writing    flu- 
Most  cases  are  unable  to  realize  the  copy  as  different  from 
the 


Fuller:  Mirror-Writing  255 

of  why  there  is  a  greater  tendency  for  the  left-handed  child  to 
write  mirrorwise  with  the  left  hand,  than  there  is  for  the  right- 
handed  child  to  write  mirrorwise  with  the  left  hand.  In  the 
left-handed,  the  seat  for  the  development  of  a  centre  for  written 
speech  is  presumably  in  the  right  cortex.  But  the  child  is  not 
allowed  to  use  his  left  hand  for  purposes  of  writing.  We  should 
remember  that  upon  the  use  of  the  right  hand  for  ordinary 
writing  depends  our  ability  to  write  mirrorwise  with  the  left 
hand.  Now  the  language-complex  in  the  present  case  is  such 
that  we  may  suppose  the  writing  impulses  are  carried  from  the 
right  cortex  to  the  emissary  area  of  the  left  cortex  and  thence 
to  the  right  arm.  An  extra  step  is  added.  Hence,  if  the  child 
does  occasionally  use  the  left  hand,  this  extra  step  will  be 
dropped.  His  left-handed  writing  is  therefore  simpler  than 
the  left-handed  writing  of  a  right-handed  individual.  Accord- 
ingly there  is  a  greater  tendency  for  the  impulses  to  function 
unaltered  in  the  left-handed  child.  What  seems  to  me  to  be  a 
confirmation  of  this  opinion  is  given  by  Hughes33  in  a  report 
upon  his  own  experience.  He  was  congenitally  left-handed  but 
was  taught  to  write  with  his  right  hand.  He  was  troubled  for  a 
number  of  years  by  the  difficulty  he  experienced  in  so  writing. 
Finally  he  hit  upon  the  device  of  writing  everything  with  his 
left  hand  mirrorwise,  on  thin  transparent  paper,  and  turning 
these  sheets  over  when  he  wished  to  read  them.  Left-handed 
mirror-writing  obviated  all  the  tediousness  of  rightward  right- 
handed  script.  I  postulate  that  a  writing-centre  was  developed 
by  the  right-handed  practice;  that  left-handed  rightward  writ- 
ing would  necessitate  reforming  this  complex  into  entirely 
different  relations ;  and  that  the  primary  facility  of  left-handed 
use  tipped  the  scales  in  favor  of  an  automatic,  rather  than  of 
an  attentive  control.  Any  double-centre  hypothesis  (which 
Hughes  himself  favors)  would  be  inadequate,  because  if  there 
was  a  separate  centre  in  the  left  cortex,  it  would  be  this  centre 
which  would  be  more  highly  developed  by  practice  of  the  right 
hand;  the  "overflow"  into  the  right  cortex  would  be  relatively 
less,  and  the  difficulty  of  writing  automatically  with  the  left 


256     University  of  California  Publications  in  Psychology  CV°L-  2 

hand  would  be  greater  instead  of  less  than  that  of  the  right 
hand,  in  spite  of  the  fact  of  left-handedness. 

While  there  is  probably  some  such  contributing  factor  as 
that  outlined  above,  the  safest  and  best  explanation  lies  in  the 
simple  fact  that  the  left  arm  of  the  left-handed  child  is  the  one 
preferred  for  all  of  the  delicate  operations  ordinarily  performed 
by  the  right  hand.  Use  of  the  left  hand  for  writing  will  there- 
fore be  a  more  thoughtless,  a  more  automatic,  reaction  than  a 
similar  action  by  one  who  is  right-handed.  And  an  automatic 
writing  presupposes  a  proportionate  increase  in  the  control  of 
the  motor  complex  of  writing;  which  in  turn,  is  more  favorable 
to  reversed  writing.  It  is  a  necessary  condition  that  the  child 
must  have  had  some  practice  with  his  right  hand  at  ordinary 
writing.  Otherwise,  there  will  be  no  reversals  by  the  left  hand, 
for  those  who  have  been  allowed  to  use  their  left  hand  freely 
and  from  the  first,  find  rightward  writing  as  easy  as  do  the 
right-handed. 

There  is  an  interesting  question  opened  here,  which  I  unfor- 
tunately have  thus  far  been  unable  to  investigate  satisfactorily. 
That  is,  will  left-handed  writers,  when  placed  under  the  same 
conditions  which  favor  a  left-handed  mirror-writing  by  the 
right-handed,  produce  mirror-writing  with  the  right  hand? 
According  to.  my  argument  they  certainly  should.  Obviously 
the  experimental  difficulties  would  be  far  greater.  Thus,  it  is 
a  difficult  matter  to  find  left-handed  writers  who  have  not  at 
some  time  been  forced  to  practice  right-handed  writing.  Such 
practice  would,  of  course,  introduce  a  new  element  into  the 
writing  complex,  and  make  these  subjects  unamenable  to  cor- 
responding tests  given  the  purely  right-handed  or  left-handed 
writer.  Of  numerous  left-handed  persons  investigated,  but  one 
could  claim  entire  freedom  from  attempts  to  enforce  the  use  of 
the  right  hand.  The  right-handed  writing  of  this  reagent  was 
subject  to  experimentally  induced  reversals  in  a  manner  anal- 
ogous in  every  respect  to  the  left-handed  writing  of  right- 
handed  individuals.  That  is,  suggestions  as  to  the  purpose  of 
the  investigation  were  as  carefully  avoided,  the  tests  were 


1916]  Fuller:  Mirror-Writing  257 

similar,  and  reversals  were  as  easily  elicited  as  in  the  average 
right-handed  subject.  I  found  greater  average  difficulty  in 
getting  a  right-handed  reversal  in  those  who  had  in  the  past 
practiced  somewhat  with  the  right  hand.  This  I  attribute  to 
the  fact  that  it  is  relatively  a  more  automatic  process  for  them 
to  write  rightwards  with  the  right  hand,  due  to  the  practice 
they  have  received  in  this  action.  Carrying  this  division  to  its 
extreme,  we  have  those  who  have  learned  to  write  correctly  with 
the  left  hand,  but  have  subsequently  been  ' '  broken ' '  and  trained 
in  the  use  of  the  right  hand.  They  are  especially  unlikely  to 
give  any  clear-cut,  consistent,  spontaneous  reversals  by  either 
hand.  It  seems  not  improbable  that  these  individuals  have 
developed  two  writing-centers,  one  for  rightward  left-handed 
writing  which,  according  to  my  argument,  would  lead  to  right- 
handed  mirror-writing;  and  one  for  rightward  right-handed 
writing.  Such  a  case  is  given  by  Acker1 — a  boy  of  ten 
years,  broken  of  left-handedness,  who  wrote  with  equal  facility 
in  four  different  ways,  viz. :  mirror-writing  with  either  hand 
and  rightward  writing  with  either  hand.  I  experimented  on 
two  left-handed  children  who  were  being  "broken"  and  found 
it  an  easy  matter  to  develop  them  into  similar  cases. 

Let  us  consider  also  those  instances  where  there  is  a  perma- 
nent injury  to  the  right  arm,  and  an  acquired  facility  in  right- 
ward  left-handed  writing.  The  writing  is  at  first  a  slow, 
labored,  attentively  controlled  "drawing",  typical  of  the  ordi- 
nary left-handed  attempt  at  writing.  But  this  improves  rapidly, 
and  the  writing  comes,  to  have  much  of  the  automatism  charac- 
teristic of  ordinary  right-hand  writing;  yet  is  seldom,  if  ever, 
as  completely  automatic.  Separate  ' '  centre ' '  for  mirror-writing 
is  hence  superfluous,  and  is  probably  not  formed,  although  an 
additional  centre  for  left-handed  left-to-right  writing — requiring 
as  it  would  an  entirely  new  set  of  kinesthetic  responses — may 
presumably  be  formed  by  practice. 


258     University  of  California  Publications  in  Psychology  [VoL-  2 

4.  EECAPITULATION 

My  argument  may  be  summarized  as  follows : 
Mirror-writing  depends  upon  two  conditions.  The  one  is 
the  physiological  element  which  embraces  (a)  the  same  single 
grapho-motor  memory  centre  for  written  symbols  that  is  em- 
ployed for  ordinary  right-handed  writing,  and  (b)  the  identical 
sensory-motor  relation  that  left-handed  reversed  writing  bears 
to  right-handed  rightward  writing.  Hence  there  is  a  predispo- 
sition towards  unpracticed  left-handed  mirror-writing  which 
exists  coextensively  with  the  ability  to  write  with  the  right  hand. 
There  exists  no  such  complex  for  left-handed  centripetal  writing. 
Mirror-writing  is  a  relatively  rare  phenomenon.  Therefore,  it 
must  depend  upon  the  disturbance  of  some  part  of  the  writing 
apparatus  other  than  the  motor ;  for  the  integrity  of  the  grapho- 
motor  centre  and  the  commisural  paths  is  the  very  foundation 
upon  which  mirror-writing  is  based.  This  is  the  second  condition, 
the  psychological  element.  The  psychological  governor  which 
supervises  our  ordinary  writing,  must  be  so  rearranged  or 
altered  that  the  psysiological  provision  for  mirror-writing  is 
given  an  opportunity  to  act,  or,  perhaps,  is  encouraged  or  stim- 
ulated to  independent  action. 

The  most  striking  generalization  to  be  drawn  from  observa- 
tions on  mirror-writing  is  that  even  in  the  most  favorable  condi- 
tions for  mirror-writing  there  is  a  great  deal  of  individual  vari- 
ation; that  is,  in  any  condition,  such  as  hypnosis,  one  subject 
will  write  entirely  mirrorwise,  while  another  can  scarcely  be 
induced  to  write  at  all  in  this  style.  I  find  exactly  the  same 
relation  in  the  description  of  those  cases  which  occur  spon- 
taneously. The  pathological  conditions  mentioned  on  pp.  201-202 
are  relatively  common.  Yet  mirror-writing  is  so  rare  as  to  cause 
immediate  comment  whenever  it  occurs.  This  may  be  due  to 
the  fact  that  only  infrequently  do  these  patients  attempt  to 
use  the  left  hand  for  writing,  in  which  case  mirror-writing 
could  be  expected  in  every  instance  when  these  patients  were 
asked  to  use  the  left  hand.  Or,  it  may  be  that  there  is  some 


1916]  Fuller:  Mirror-Writing  259 

particular  disorganization  which  occurs  inconstantly  in  all  of 
the  conditions  favorable  to  mirror-writing.  And  this  in  truth 
more  nearly  approaches  the  conditions  which  my  own  theory 
emphasizes.  The  more  that  the  psychological,  or  higher,  parts 
of  the  nervous  system  are  disorganized,  the  more  confidently 
may  we  expect  a  left-handed  reversed  writing  to  result.  Again, 
the  disorganization  must  be  great  enough  to  pass  a  certain  min- 
imal limit  before  one  may  expect  spontaneous,  complete  left- 
handed  reversals.  And  more  particularly,  we  may  expect  that 
if  the  disorganization  is  of  a  specialized  kind,  one  that  will 
dissociate  the  automatic  from  the  sensory  and  attentive  control 
of  the  muscles,  or,  a  step  more,  divert  writing  activity  to 
the  physiological  element,  the  dissociation  need  be  much  less 
than  if  the  disorganization  is  general.  This  is  observed  partic- 
ularly when  considering  the  relatively  circumscribed  disturb- 
ance occasioned  by  the  majority  of  my  experiments,*  as  against 
the  great  disorder  of  many  of  the  pathological  states  in  which 
mirror-writing  occurs,  notably  the  insanities. 

There  are  two  additional  forms  of  left-handed  mirror-writing 
—viz.,  the  deliberate,  intentional,  attentive  and  the  fragmentary. 
These  also  depend,  but  to  a  much  less  degree,  upon  the  crossing 
of  the  secondary  impulse.  In  the  first  of  these  forms,  the  less 
conscious  or  intentional  the  mirror-writing  is,  the  greater  is 
this  dependence.  Conversely,  the  more  attention  we  devote  to 
these  movements,  which  are  a  new  experience  to  our  higher  con- 
sciousness, the  more  dependence  is  placed  upon  the  visuo- 
psychic  and  association  areas  for  guidance.  In  the  second 
type,  there  is  a  tendency  for  some  reagents  to  make  fragmentary 
reversals  with  the  left  hand,  which  depend  to  some  extent  upon 
the  commissural  paths,  but  as  the  reversals  are,  with  lower  grades 
of  experience,  frequent  with  the  right  hand,  the  ultimate  explan- 
ation is  found  in  the  confusion  of  lateral  relationships.  This 
type  can  not  properly  be  considered  as  a  representative  of  true 
mirror-writing. 


*See  pp.  215  ff. 


260     University  of  California  Publications  in  Psychology  tv°L-  2 

PART  IV 

RELATION  OF  CONCLUSIONS  TO  EARLIER 
EXPLANATIONS 

Referring  to  the  classification  of  previous  hypotheses  as  given 
on  page  214  I  find  that  while  the  definitions  of  the  occurrence 
of  certain  tendencies  in  movements  are  perhaps  true,  Group  A 
does  not  comprehend  the  fundamental  reason  for  mirror-writing. 
Of  this  group,  the  observations  of  Durand  and  Peckham  strike 
nearest  to  the  real  cause  of  mirror-writing)  in  that  they  intro- 
duce quite  prominently  the  factor  of  attention;  Peckham 
including  as  well  a  physiological  basis  for  the  phenomenon. 

The  criticism  of  Groups  B  and  C  are  several,  and  may  be 
best  made  clear  by  referring  to  the  observations  which  seem  to 
favor  the  hypothesis  of  a  single  centre,*  and  in  addition  to  the 
criticisms  of  Hale  and  Kuhf  and  of  Sweeney  %  I  have  shown 
that  it  is  possible  to  escape  from  the  wholly  unsatisfactory  idea 
of  the  presence  of  a  definite  mirror-writing  centre;  and  that 
the  theory,  rather  than  suffering  from  this  omission,  is  actually 
rendered  the  stronger.  The  study  of  these  groups  brings  out  a 
matter  of  even  greater  moment,  namely,  that  the  physiological 
aspect  of  mirror-writing,  however  it  be  answered,  is  but  a  minor 
part  of  the  solution  of  the  question. 

With  the  observations  classed  as  group  D,  I  agree.  However, 
the  same  criticism  as  was  made  of  group  A  applies  here — the 
explanation  is  not  sufficiently  comprehensive.  In  every  case  of 
true  mirror-writing  (which  it  should  be  remembered,  does  not 
include  reversals  by  the  hand  accustomed  to  writing)  there  must 
be  a  disturbance,  a  deflection,  of  the  mental  content,  a  dissoci- 
ation of  attention. 

Group  E,  in  placing  prominence  upon  a  factor  of  visual 
imagery,  neglects  the  proper  significance  of  the  normal  physio- 
logical, or  grapho-motor,  element  as  being  the  fundamental 


*See  pp.  227-237,  also  group  D,  pp.  210-211. 
tSee  pp.  211-212. 
JSee  pp.  212-213. 


Fuller:  Mirror-Writing  261 

\ 

means  by  which  true  mirror-writing  is  accomplished.  I  agree 
with  the  conclusion  of  Hale  and  Kuh  on  fragmentary  right- 
handed  reversals,  but  do  not  class  this  type  as  a  representative 
of  true  mirror-writing.  I  cannot  agree  with  their,  or  with 
Sweeney's  answer  to  the  question,  why  mirror- writing  is  not 
inverted :  though  their  observations  are  sound,  and  are  sufficient 
to  account  for  right-handed  reversals,  yet  the  motor  relations  as 
I  have  described  them  would  not  permit  of  true  inverted  writing. 
I  agree  with  Downey  in  group  F,  that  there  is  a  motor  as 
well  as  a  visual  representation  of  a  movement.  My  experience 
has  been  that  the  majority  of  subjects,  when  voluntarily  revers- 
ing their  writing,  exercise  their  attention  principally  to  force  the 
writing  in  a  reversed  direction.  The  actual  reversal  of  the 
letters  is  by  the  guidance  of  the  grapho-motor  system.  Atten- 
tive guidance  is  required  only  when  a  confusing  or  relatively 
unfamiliar  letter  brings  uncertainty  to  the  automatic  control. 
Many  of  the  earlier  explanations  seem  to  be  devised  in  view 
of  the  special  conditions  offered  by  some  particular  case  of 
mirror-writing.  Explanations  of  different  observers  have  there- 
fore differed  widely.  I  have  shown  that  all  the  reported  causes 
of  mirror-writing,  or  conditions  favoring  it*  have  characteristics 
in  common.  Further,  I  have  shown  that  typical  mirror-writings 
can  be  controlled  by  experimental  methods,  and  that  to  study 
mirror-writing  we  do  not  need  to  seek  the  spontaneously  occur- 
ing  cases,  as  has  been  done  in  the  great  majority  of  reports. 
Lastly,  I  have  shown  that  mirror-writing  is  a  simple,  direct  and 
unified  process,  not  at  all  as  complicated  and  disconnected  as 
a  comparison  of  the  several  findings  would  lead  one  to  expect. 
Its  explanation  is  simply  that  certain  impulses  which  do  not 
ordinarily  function,  are  by  the  conditions  in  which  mirror- 
writing  occur  allowed  to  do  so.  These  conditions,  instead  of 
being  a  more  or  less  unconnected  set  of  symptoms  as  indicated 
on  pp.  201-202,  I  have  shown  to  rest,  with  the  experimental  condi- 
tions, upon  the  common  basis  of  dissociation. 
Transmitted  June  20,  1914. 


*See  pp.  201-202. 


262     University  of  California  Publications  in  Psychology  tVoL-  2 


KEFEKENCES 

1.  ACKER,  G.  N.:     "Two  Mirror-writers",  Arch,  pediat.,  Vol.  XVI 
(1894),  pp.  676-678. 

2.  ABT,   G.:      "L'ecriture    en    miroir",    Annee   psychol.,   Vol.    VIII 
(1902),  pp.  221-256. 

3.  ALLEN,  F.  J.:      "Mirror-writing",  Brain,  Vol.   XIX    (1896),   pp. 
385-387. 

4.  AUDEN,  G.  A.:     "Mirror-writing",  Brit.  jour,  children's  dis.,  Vol. 
VI  (1909),  pp.  529-535. 

5.  BALDWIN,    J.    M.:      Dictionary    of   philosophy    and    psychology 
(New  York,  Macmillan,  1902),  Vol.  II,  pp.  86-87. 

6.  BALLET,   G.:     "L'ecriture  en  miroir",  XHIe   Cong,  internat.   de 
med.  (1900),  p.  61. 

7.  BALLET,  G.  H.:    "L'ecriture  de  Leonard  de  Vinci;  contribution  a 
1'etude    de    1'ecriture    en   miroir",    Nouvelle   iconographie   de    la    Sal- 
petriere,  Vol.  XIII  (1900),  pp.  597-614. 

8.  BARR,  M.  W.:     Mental  defectives   (Philadelphia,  P.  Blakiston's 
Son  &  Co.,  1910),  pp.  228-230. 

9.  BASTIAN,  H.   C.:     Aphasia  and  other  speech  defects    (London, 
H.  K.  Lewis,  1898),  pp.  298-300. 

10.  BIANCHI,  M.  D.:     "Changes  in  the  handwriting  in  relation  to 
pathology",  Alienist  and  neurol.,  Vol.  IV  (1883),  pp.  566-589. 

11.  BRUCE,  L.  C.:     "Notes  of  a  case  of  dual  brain  action",  Brain, 
Vol.  XVIII   (1895),  pp.  54-65. 

12.  BUCHANNAN,    L.  i     "Mirror-writing,    with    notes    on    a    case", 
Opthalmoscope,  Vol.  VI  (1908),  pp.  156-159. 

13.  BUCHWALD:     "Spiegelschrift  bei  Hirnkranken",  Berliner  klin. 
Woch.,  Vol.  XV  (1878),  pp.  6-8. 

14.  BURR,  C.  W.,  and  CROW,  C.  B.:     "Mirror-writing  and  other  asso- 
ciated movements  occurring  without  palsy",  Jour.  nerv.  and  ment.  dis., 
Vol.  XL  (1913),  pp.  300-302. 

15.  CAHEN-BRACH:      "Ueber    das    Vorkommen    von    Spiegelschrift, 
besonders  im  Kindesalter",  Deutsches  Archiv.  fur  klin.  Med.,  Vol.  LI 
(1893),  pp.  141-160. 

16.  CAMPBELL,  H. :    "Right-handedness  and  left-brainedness",  Lan- 
cet, Vol.  I  (1903),  p.  132. 

17.  CHURCH,  A.,  and  PETERSON,  F.:     Nervous  and  mental  diseases 
(Philadelphia  and  New  York,  W.  B.  Saunders  &  Co.,  1911),  p.  69. 

18.  CLAPHAM,    A.:     "A    case    of   mirror-writing",    Quarterly   med. 
jour.,  Vol.  Ill  (1895),  pp.  333-335. 

19.  CUSHNY,   A.    R.:      Pharmacology   and   therapeutics    (Philadel- 
phia and  New  York,  Lea  &  Febiger,  1911). 

20.  DOWNEY,  J.  E.:     "Control  processes  in  modified  handwriting: 


1916]  Fuller:  Mirror-Writing  263 

an  experimental  study",  Psych,  rev.,  monog.  suppl.,  Vol.  IX  (1908),  pp. 
1-148. 

21.  DURAND,  M.:   "De  1'ecriture  en  miroir,  etude  sur  1'ecriture  de 
la  main  gauche  dans  ses  rapportes  avec  1'aphasie",  Mem.  et  lull,  so- 
ciete  de  med.  et  de  chir.  de  Bordeaux  (1882),  pp.  517-539. 

22.  ELDER,    W.:      Aphasia    and    the    cerebral  speech    mechanism 
(London,  H.  K.  Lewis,  1897),  p.  214. 

23.  ERLENMEYER,  A.:     "Die  Schrift",  Bull.  soc.  de  med.  ment.  de 
Belgique:  Gand  et  Leipzig,  No.  21   (1881),  pp.  110,  114. 

24.  ERLENMEYER,    A.:   Die    Schrift,    Grundzuge    ihrer    Physiologic 
und  ihrer  Pathologic  (Stuttgart,  1879). 

25.  FIGUERA,  F.:     "Contribution  a  1'etude  de  l'6criture  en  miroir 
chez  les  enfants",  Ann.  de  med.  et  chir.  inf.,  Vol.  VI  (1902),  pp.  145-154. 

26.  FREEMAN,  F.  N. :     "Preliminary  experiments  on  writing  reac- 
tions", Psych,  rev.,  monog.  suppl.  No.  34  (1907),  pp.  301-333. 

27.  GAUTHIER,    E.:      Des    mouvements    automatics    rhythmiques 
(Paris,  Bordier  et  Michalon,  1898). 

28.  GOULD,  G.  M.:     Right-handedness  and  left-handedness   (Phila- 
delphia and  London,  J.  B.  Lippincott  Co.,  1908). 

29.  GOULD,  G.   M.:    "Study  of  a  case  of  two-handed  synchronous 
writing",  Med.  record,  Vol.  XXII  (1907),  pp.  717-752. 

30.  GOWERS,    W.     R. :     "Right-handedness    and    left-brainedness", 
Lancet,  Vol.  II  (1902),  p.  1719. 

31.  HALE,  A.  B.,  and  KUH,  S.:     "Mirror-writing  and  the  inverted 
image",  Journ.  Am.  Med.  Assn.,  Vol.  XXXVII  (1901),  pp.  1380-1385. 

32.  HOWELL,  W.  H.:     Text-book  of  physiology    (Philadelphia  and 
London,  W.  B.  Saunders  Co.,  1912). 

33.  HUGHES,  E.:     "Mirror-writing",  Lancet,  Vol.  I  (1908),  p.  188. 

34.  HUGHLINGS- JACKSON,  J. :  "On  affections  of  speech  from  disease 
of  the  brain",  Brain,  Vol.  I  (1879),  pp.  304-330;  Brain,  Vol.  II  (1880), 
pp.  203-223. 

35.  IRELAND,  W.  W.:     Mental  affections  of  children  (London,  J.  & 
A.  Churchill,  1900),  p.  329. 

36.  IRELAND,  W.  W.:     Blot  upon  the  brain  (Edinburgh,  1893). 

37.  IRELAND,  W.  W.:     "On  Mirror-writing",  Alien,  and  neurol.,  Vol. 
XIV  (1893),  pp.  100-108. 

38.  IRELAND,  W.  W.:     "On  mirror-writing  and  its  relation  to  left- 
handedness  and  cerebral  disease",  Brain,  Vol.  XV  (1882),  pp.  361-367. 

39.  JASTROW,  J.:     "A  study  of  involuntary  movements",  Am.  jour, 
psych.,  Vol.  IV  (1892),  pp.  398-407. 

40.  JONES,  C.  D.:    "Mirror-writing,"  Boston  med.  and  surg.  jour., 
Vol.  CXLIX  (1903),  p.  515. 

41.  KEROVAL,  P.:     Le  langage  ecrit,  ses  origines,  son  development 
et  son  mecanisme  intellectuals  (Paris,  1897). 

42.  KINGMAN,  R.:     "Mirror-writing  in  the  right-handed",  Brooklyn 
med.  jour.,  Vol.  XIX  (1905),  pp.  114-118. 


264     University  of  California  Publications  in  Psychology  [VOL-  2 

43.  KRAFFT-EBING,   R.   VON:    Hypnotism    (New  York   and   London, 
G.  P.  Putnam's  Sons,  1896),  p.  29. 

44.  LAPRADE,   A.:     Contribution  a   I'etude   de   I'ecriture   en   miroir 
(Paris,  Oilier-Henry  &  Cie,  1903). 

45.  LEICHTEN STERN,  0.:     "Ueber  die  Schreibweise  Linkshandiger", 
Deutsche  med.  woch.,  Vol.  XVIII  (1892),  pp.  942-944. 

46.  LICKLEY,  J.   D.:     The  nervous  system    (New  York,  Longmans, 
Green  &  Co.,  1912). 

47.  LIST,    W.    G.:      "A    case    of    mirror-writing    in    an    epileptic 
negress",  Phil,  med,  jour.,  Vol.  VII  (1901),  pp.  130-132. 

48.  LUEDDECKENS,     F.  i     Rechts-     und     Linkshandigkeit     (Leipzig, 
W.  Engelman,  1900). 

49.  MEIGE,  H. :      "Les  mouvements  en  miroir;    leurs  applications 
pratiques  et  therapeutiques",  Cong.  med.  alien,  et  neurol.  de  France, 
Vol.  XI  (1901),  pp.  380-390. 

50.  MILLS,  C.  K.:     "Mirror-writing",  J.  nerv.  and  ment.  dis.,  Vol. 
XXI  (1894),  pp.  85-91. 

51.  MORE,  J.:     "Right-handedness",  Lancet,  Vol.  I  (1903),  p.  613. 

52.  NICOLLE,  C.,  and  HALIPR&,  A.:     "L'ecriture  en  miroir  cecit6  ver- 
bale  pure  et  centre  de  1'agraphie",  La  Presse  med.,  Vol.  Ill    (1895), 
pp.  748-750. 

53.  OHM,     J.:     "Umgekehrte     Schrift    bei     einem     linkshandigen 
Kinde",  Klin.  f.  psychische  u.  nerv.  Krankh.,  Vol.  Ill  (1908),  pp.  285- 
290. 

54.  PATON,  S.:     Psychiatry  (Philadelphia  and  London,  J.  B.  Lippin- 
cott  Co.,  1905),  pp.  372,  383. 

55.  PECKHAM,    G.:     "Mirror-writing    and    the    pathological    chiro- 
graphy  of  nervous  origin",  Med.  record,  Vol.  XXIX  (1886),  pp.  226-230. 

56.  PENDRED,    U. :     "A    case    of    mirror-writing",    Lancet,    Vol.     I 
(1908),  p.  20. 

57.  PILLSBURY,  W.  B.:  "The  place  of  movement  in  consciousness", 
Psych,  rev.,  Vol.  XVIII  (1911),  pp.  83-99. 

58.  ROBERTSON,  T.  B.:     "Further  studies  in  the  chemical  dynamics 
of  the  central  nervous  system",  Part  2,  Folia  neuro-biologica  (1913). 

59.  ROTCH,  T.  M.:     Pediatrics  (Philadelphia,  J.  B.  Lippincott  Co., 
1896),  pp.  673-675. 

60.  RUDOLF,   R.    D.:     "Mirror-writing",   Canadian  pract.   and  rev., 
Vol.  XXVIII  (1903),  pp.  83-88. 

61.  RUSSELL,  J.  W. :     "A  case  of  mirror-writing",  Birmingham  med. 
rev.,  Vol.  LXVIII  (1900),  pp.  95-101. 

62.  SHERRINGTON:      The  integrative  action  of  the  nervous  system 
(New  York,  Charles  Scribner's  Sons,  1906). 

63.  SMITH,   H.:     "On  mirror-writing",  Lancet,  Vol.   II    (1879),   p. 
712. 

64.  SWEENEY,    A.:     "Mirror-writing,    inverted    vision    and    allied 
ocular  defects",  St.  Paul  med.  jour.,  Vol.  II  (1900),  pp.  374-391. 


1916]  Fuller:  Mirror-Writing  265 

65.  THOMPSON,  M.  E. :     Psy etiology  and  pedagogy  of  writing  (Balti- 
more, Warwick  &  York,  Inc.,  1911). 

66.  TUCKER,  M.  S.:     "Involuntary  movements",  Am.  jour,  of  psych., 
Vol.  VIII   (1897),  pp.  394-404. 

67.  TUKE,  D.  H. :     Dictionary  of  psychological  medicine   (London, 
J.  &  A.  Churchill,  1892),  Vol.  I,  p.  573. 

68.  VOGT,   C.:      "L'ecriture   au   point   de   vue   pathologique",   Rev. 
scientifique,  Vol.  XVIII  (1880-2),  pp.  122M232. 

69.  WILKS,   S.:     "Right-handedness  and   left-handedness",  Lancet, 
Vol.  II  (1902),  p.  1658. 

70.  WOOD,  H.  C.:     A  treatise  on  therapeutics   (Philadelphia,  J.  B. 
Lippincott    Co.,     1887),    pp.     264-268.      Original    article— Proc.    Am. 
philosoph.  soc.,  Vol.  XI  (1869),  p.  226. 

71.  WRAY,   C.:     "Right-handedness   and   left-brainedness",   Lancet, 
Vol.  I  (1903),  p.  683. 


UNIVERSITY  OF  CALIFORNIA  PUBLICATIONS— (Continued) 

PHILOSOPHY,  Vol.  2  (Continued) 

4.  The  Mystical  Element  in  Hegel's  Early  Theological  Writings,  by  George 

Plimpton  Adams.    Pp.  67-102.    September,  1910 — ....     .35 

5.  The  Metaphysics  of  Historical  Knowledge,  by  DeWitt  H.  Parker.    Pp. 

103-186.     February,  1913 .: ~ ~ -     .85 

AMERICAN  ARCHAEOLOGY  AND  ETHNOLOGY. — Alfred  L.  Kroeber,  Editor.  Price 
per  volume  $3.50  (volume  I,  $4.25).  Volumes  I-X  completed.  Volumes  XI  and  Xn 
in  progress. 

BOTANY. — W.  A.  Setchell,  Editor.  Price  per  volume  $3.50.  Volumes  I  (pp.  418),  EC  (pp. 
354),  ni  (pp.  400)  and  IV  (pp.  397)  completed.  Volumes  V  and  VI  in  progress. 

CLASSICAL  PHILOLOGY. — Edward  B.  Clapp,  William  A.  Merrill,  Herbert  C.  Nutting, 
Editors.  Price  per  volume  $2.50.  Volume  I  (pp.  270)  completed.  Volumes  n  and 

III  in  progress. 

ECONOMICS.— Carl  C.  Plehn,  Editor.  Volumes  I  (632  pages,  price  $5.00),  U  (461  pages, 
price  $4.00),  and  III  (451  pages,  price  $3.50)  completed.  Volume  IV  in  progress. 

EDUCATION.— Alexis  F.  Lange,  Editor.  Volumes  I  (424  pages,  price  $3.50),  HI  (447 
pages,  price  $3.50),  and  IV  (258  pages,  price  $2.50)  completed.  Volumes  n  and  V 
in  progress. 

GEOGRAPHY. — Ruliff  S.  Holway,  Editor.    Price  per  volume  $3.50.    Volume  I  in  progress. 

GEOLOGY. — Andrew  C.  Lawson  and  John  C.  Merriam,  Editors.  Price  per  volume  $3.50; 
volumes  VIII  and  following,  $5.00.  Volumes  I  (pP-  428),  n  (pp.  450),  in  (pp.  475), 

IV  (pp.  462),  V  (pp.  458),  VI  (pp.  454),  VII  (pp.  505),  and  VIH  (pp.  583)  completed. 
Volume  IX  in  progress. 

HISTORY.— Henry  Morse  Stephens  and  Herbert  E.  Bolton,lEditors.    Volumes  I  (pp.  406), 

$3.00,  II  (pp.  278)  $2.00,  III  (pp.  510)  $3.50,  carriage  extra. 
MATHEMATICS.— Mellen  W.  Haskell,  Editor.     Price  per  volume  $3.50.     Volume  I  in 

progress. 
MODERN  PHILOLOGY.— Charles  M.  Gayley,  Hugo  K.  Schilling,  Rudolph  Schevill,  Editors. 

Price  per  volume  $2.50.    Volume  I  (pp.  400),  n  (pp.  373)  completed.    Volumes  in 

and  IV  in  progress. 
ZOOLOGY.— W.  E.  Ritter  and  Charles  A.  Kofoid,  Editors.    Price  per  volume  $3.50;  volumes 

XI  and  following,  $5.00.    Volumes  I  (pp.  317),  II  (pp.  382),  HI  (pp.  383),  IV  (pp. 

393),  V  (pp.  440),  VI  (pp.  478),  VII  (pp.  446),  VIII  (pp.  357),  IX  (pp.  365),  X  (pp. 

417),  and  XI  (pp.  538)  completed.    Volumes  XH  to  XVI  in  progress. 
MEMOIRS  OF  THE  UNIVERSITY  OF  CALIFORNIA  (Quarto). 

Vol.  1.    1.  Triassic  Ichthyosauria,  with  Special  Reference  to  the  American  Forms, 

by  John  C.  Merriam.    Pp.  1-196,  plates  1-18.    September,  1908 $3.00 

2.  The  Fauna  of  Rancho  La  Brea.    Part  I.    Occurrence,  by  John  C.  Mer- 

riam.   Pp.  197-213,  plates  19-23.    November,  1911 , 30 

3.  The  Fauna  of  Rancho  La  Brea.    Part  II.    Canidae,  by  John  C.  Merriam. 

Pp.  215-272,  plates  24-28,  35  text  figures.    October,  1912 _ 80 

Vol.  2.  The  Silva  of  California,  by  Willis  Linn  Jepson,  480  pages,  with  85  plates 
and  3  maps.  December,  1910.  Sewed,  in  paper  covers,  $5;  bound  in 
cloth,  $7.50.  (By  express,  $8.40.) 

Vol.  3.  Business  Cycles,  by  Wesley  Clair  Mitchell,  xviii  -f  610  pages,  with  77 
charts.  September,  1913.  Sewed,  in  paper  covers,  $5;  bound  in  buck- 
ram, $7.50.  (Expressage,  50  cents  extra.) 

Vol.  4.  1.  The  Battle  of  the  Seven  Arts,  a  French  Poem  by  Henri  d'Andeli,  Trou- 
vere  of  the  Thirteenth  Century.  Edited  and  Translated,  with  Intro- 
duction and  Notes  by  Louis  J.  Paetow.  Pp.  1-63,  plates  1-10.  July, 
1914  _ 75 

Other  series  in  Agricultural  Sciences,  Botany,  Engineering,  Entomology,  Lick  Observa- 
tory Bulletins,  Lick  Observatory  Publications,  Physiology,  Pathology,  Prize  Essays,  and 
Publications  of  the  Academy  of  Pacific  Coast  History. 

UNIVERSITY  OF  CALIFORNIA  CHRONICLE.— An  official  record  of  University  life, 
issued  quarterly,  edited  by  a  committee  of  the  faculty.  Price  $1  per  year.  Current 
volume  No.  XVIII. 

ADMINISTRATIVE  BULLETINS  OF  THE  UNIVERSITY  OF  CALIFORNIA.— Edited  by 
the  Recorder  of  the  Faculties.  Includes  the  Register,  the  President's  Report,  the 
Secretary's  Report,  and  other  oflicial  announcements. 

Address  all  orders,  or  requests  for  information  concerning  the  above  publications  to 
The  University  of  California  Press,  Berkeley,  California. 


RETURN  TO  the  circulation  desk  of  any 
University  of  California  Library 

or  to  the 

NORTHERN  REGIONAL  LIBRARY  FACILITY 
Bldg.  400,  Richmond  Field  Station 
University  of  California 
Richmond,  CA  94804-4698 

ALL  BOOKS  MAY  BE  RECALLED  AFTER  7  DAYS 

•  2-month  loans  may  be  renewed  by  calling 
(510)642-6753 

•  1-year  loans  may  be  recharged  by  bringing 

books  to  NRLF 

•  Renewals  and  recharges  may  be  ma< 

days  prior  to  due  date. 

• 

DUE  AS  STAMPED  BELOW 


12,000(11/95) 


991S5J 


THE  UNIVERSITY  OF  CALIFORNIA  LIBRARY 


